Will an AR bolt seat a bullet, or just stop?

Cupcake · August 27th, 2008, 08:17 AM

I understand that sometimes to figure out the maximum length for a cartridge for a specific rifle, one can barely seat the bullet in the case, then insert it into the chamber and slam the bolt home to seat the bullet th rest of the way. Then you take the round out and measure it, then set up to seat your rounds .001-.003 shorter.

Anyhoo, does this work with a semiauto where you can't force the bolt home (specifically and AR15)?

dukalmighty · August 27th, 2008, 11:45 AM

You can either by using the forward assist or removing the upper receiver and pushing the bolt carrier forward with force.One thing you might want to consider is if you run the bullet out that far out of the case it may not fit in the magazine

Ram Rod · August 27th, 2008, 03:05 PM

Quote:

Will an AR bolt seat a bullet, or just stop?

First off...I wouldn't suggest trying this with anything besides an empty, deprimed case. Secondly...this shouldn't be attempted in the first place, and be ready to get your bullet stuck in the rifling if you do. There are tools made for gauging OAL and seating depth without using the rifle bolt. Since your standard AR-15 upper can be removed from the lower, you can do this pretty much as you would a bolt action rifle. If you close a bolt on a 'make-up' round, you won't actually know how much of the rifle bullet has actually been pushed into the rifling after it actually stops and subsequently starts backing into the case itself. OAL measurements are made with modified cases where the neck isn't actually exerting tension on the bullet itself. Most of my loads for my bolt actions fall within .002 to .006" off the rifling. While crude methods such as the chambering method you describe might get one 'in the ball park' it's going to do nothing more than get you within usual factory tolerances. It may also mislead one into running the bullet out just a bit more and the possibilities of overpressure if your manufactured rounds don't have enough free bore distance to the rifling. While this situation may be less of a danger in the bolt action rifle because of the engineering and design....I figure it would be even more of a hazard attempting with a bolt design involving several pieces that rely on small parts such as the AR-15 gas operated system depending on a cotter pin, and some screws to hold it all together. If you are already into reloading, you should have some of the basic tools. My suggestion is to get the extra tools to make dependable OAL and bullet seating measurements. Reloading won't save you anything if you destroy your rifle or loose an eye or hand. Just my 2¢

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Cabela's -- Stoney Point Chamber-All™ OAL Gauges
OAL
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Cupcake · August 27th, 2008, 04:21 PM

Thanks for the $.04. It would seem that even if I can find the "perfect" length this way, they most likely wouldn't feed or maybe not even fit in the mags. Guess I'll make a few small batches centered around 2.260" and stick with that.

Redneck Repairs · August 27th, 2008, 04:34 PM

Quote:

the "perfect" length

QUIT THAT CRAP !! You simply cannot load an ar as you would your favorite bolt . Yes the ar does chamber somewhat consistent when you get lug lock , However no matter how accurate the AR might be it is a battle rifle with slop built into the design . This means you will face large issues " forming brass " to a rifle and loading for that chamber . Tho the AR can be tweaky as any rifle , brass is not an area we can really work due to the design . If your serious about accuracy well the cetrenly get your chamber plugged and then make sure brass is shorter than it by whatever formula you choose . fireformed or " stretched " brass will almost allways shoot better than new brass in an ar . With that being said you have to learn some new rules loading for the ar , and the first rule is not to worry about the chamber over much . Load to spec , if you need load only cases from that rifle neck sized . Put the time , effort and trouble you save into a real good trigger and i suspect you will get the groups you want .

Ram Rod · August 27th, 2008, 06:15 PM

Just a little more to add. If you are reloading for a rifle chambered for 5.56, I'd recommend sticking with 5.56 brass vs .223. Specific issues concerning the differences in case capacity and pressures have been discussed here before. I hope HotGuns will be along to add his two cents about your proposed activities soon. If all the usual things are in order, I'd stick with your loadbook data OAL as the max, and have a few different sources to review.
Here's one from the archives....I'm sure there's more.
5.56/.223 - I just dont get it

Shizzlemah · August 27th, 2008, 07:04 PM

Seat some bullets to various lengths in trimmed brass, and "color in" the bullet with a sharpie.

Chamber them, and the long ones will show rifling marks on the bullets. Go .003-.005" shorter.... BUT you may need to go shorter yet to get a round to run through the mag.

HotGuns · August 27th, 2008, 08:28 PM

There is a way to figure out the maximum length of bullet for the AR.

The first thing you need to do is color the bullet as Shizzlemah mentions.

Then break open the gun. Remove the rear pin and leave the front pin in place.

The reason for this is to remove the spring tension from the bolt, which is too stiff to get a good length. You now have the gun open, place a bullet in the chamber gently. Now take your thumb and gently push the bolt forward. I mean gently. If you do it to hard you will jam the bullet into the rifling and it wont stay in the case. You'll want the bullet to go all the way forward so that the bolt locks and the extractor hooks the case and extracts the bullet. When it does, gently extract the case and catch it with your other hand.

The blackened bullet should show some marks where it was engraved by the rifling.

Now, with a magazine, check the length of the bullet. Don't insert the bullet into the mag, first lay it along side the follower and inspect it. If it looks like the bullet is too long, forget about long loading your brass, it wont work. It will have to be limited to whatever length will go into the magazine.

If it looks like it will go into it without the nose of the bullet running into the front of the mag, go ahead and load it in the mag. Make absolutely sure that it will not run into the front of the mag. Make sure that you have at least enough clearance for the bullet to be able to move some when the rifle recoils, otherwise the bullet will hang up in the magazine when the tip of the bullet is jammed into it.

Record the overall length of the bullet and try it. Don't load it to the rifling, load it no less than .010 thousandths from the rifling, to keep pressures down and reliability up. Be sure to go at least 10% less than the maximum load and then you'll have to experiment with the function of the bullet. You can improve accuracy to a point, but there is definitely a place where you lose any advantage due to loss of function.

With that being said, it can be done if one is meticulous.

What Redneck Repairs posted has lots of merit. Its an AR and it is a battle rifle. It absolutely needs to be 100 %reliable. The chambers are a bit sloppy so that they can endure carbon and residue build up and still function.

Any accuracy gain would be minimum as compared to a bolt gun. If you happen to have a barrel with a "match" chamber, you may realize more gain. Match chambers are made to shoot matches, and although they may be more accurate, there is usually a trade off in reliability. The match guns are usually cleaned after each event and see more in the way of maintenance than the standard AR.

It will take experimentation to figure out if it is worth the extra step.I have 3 AR's and I don't do it, all of them being accurate enough for me. I do have several bolt guns that I long load for, but they are different animals altogether.

In my humble opinion, the .001-.003 that you propose it too short for a semi auto where lots of things are happening beyond your control. A bullet left for any amount of time in a hot chamber can grow longer due to thermal expansion. Also, it doesn't give much room for error and in the event that your bullets are long to begin with it is not unheard of for recoil to actually pull some of the bullets out a bit. Ten thousandths is pretty standard for long loaded bullets and it does give one a larger margin of error when reloading.

But all this means nothing if it dosent fit in the magazine.

dukalmighty · August 27th, 2008, 09:23 PM

Quote:

Originally Posted by HotGuns

There is a way to figure out the maximum length of bullet for the AR.

The first thing you need to do is color the bullet as Shizzlemah mentions.

Then break open the gun. Remove the rear pin and leave the front pin in place.

The reason for this is to remove the spring tension from the bolt, which is too stiff to get a good length. You now have the gun open, place a bullet in the chamber gently. Now take the charging handle and gently push it forward. I mean gently. If you do it to hard you will jam the bullet into the rifling and it wont stay in the case. You'll want the bullet to go all the way forward so that the bolt locks and the extractor hooks the case and extracts the bullet. When it does, gently extract the case and catch it with your other hand.

The blackened bullet should show some marks where it was engraved by the rifling.

Now, with a magazine, check the length of the bullet. Don't insert the bullet into the mag, first lay it along side the follower and inspect it. If it looks like the bullet is too long, forget about long loading your brass, it wont work. It will have to be limited to whatever length will go into the magazine.

If it looks like it will go into it without the nose of the bullet running into the front of the mag, go ahead and load it in the mag. Make absolutely sure that it will not run into the front of the mag. Make sure that you have at least enough clearance for the bullet to be able to move some when the rifle recoils, otherwise the bullet will hang up in the magazine when the tip of the bullet is jammed into it.

Record the overall length of the bullet and try it. Don't load it to the rifling, load it no less than .010 thousandths from the rifling, to keep pressures down and reliability up. Be sure to go at least 10% less than the maximum load and then you'll have to experiment with the function of the bullet. You can improve accuracy to a point, but there is definitely a place where you lose any advantage due to loss of function.

With that being said, it can be done if one is meticulous.

What Redneck Repairs posted has lots of merit. Its an AR and it is a battle rifle. It absolutely needs to be 100 %reliable. The chambers are a bit sloppy so that they can endure carbon and residue build up and still function.

Any accuracy gain would be minimum as compared to a bolt gun. If you happen to have a barrel with a "match" chamber, you may realize more gain. Match chambers are made to shoot matches, and although they may be more accurate, there is usually a trade off in reliability. The match guns are usually cleaned after each event and see more in the way of maintenance than the standard AR.

It will take experimentation to figure out if it is worth the extra step.I have 3 AR's and I don't do it, all of them being accurate enough for me. I do have several bolt guns that I long load for, but they are different animals altogether.

In my humble opinion, the .001-.003 that you propose it too short for a semi auto where lots of things are happening beyond your control. A bullet left for any amount of time in a hot chamber can grow longer due to thermal expansion. Also, it doesn't give much room for error and in the event that your bullets are long to begin with it is not unheard of for recoil to actually pull some of the bullets out a bit. Ten thousandths is pretty standard for long loaded bullets and it does give one a larger margin of error when reloading.

But all this means nothing if it dosent fit in the magazine.

The charging handle will not push the bolt closed it will only pull the bolt carrier group back,if your concerned about a slam fire remove the firing pin before seating the bullet you should be able to push on the rear of the bolt carrier group with enough force to close it then gently open with the charging handle if it's a little sticky insert a small flat blade screwdriver at the front of the bolt carrier group and gently pry it back,the main problem is if you seat the bullet longer than specs you will end up with a single shot rifle as they will not fit in the magazine,even if they go in if they drag on the magazine walls they will cause jams,the ar with good loads will shoot very accurate,experiment with powder charge,primers and crimp til you work up an accurate load for your gun.If you shoot like me that gun will probably shoot better than you.

HotGuns · August 27th, 2008, 09:28 PM

Good catch Duk...I went back and changed it. The slam fire isnt really the concern though, jamming the bullet in the rifling is. I have had to get a cleaning rod to knock out a bullet that was jammed, then you have to start back at square one.

August 27th, 2008, 08:17 AM	#1
Cupcake VIP Member Join Date: Mar 2007 Location: Michigan Posts: 2,664	Will an AR bolt seat a bullet, or just stop? I understand that sometimes to figure out the maximum length for a cartridge for a specific rifle, one can barely seat the bullet in the case, then insert it into the chamber and slam the bolt home to seat the bullet th rest of the way. Then you take the round out and measure it, then set up to seat your rounds .001-.003 shorter. Anyhoo, does this work with a semiauto where you can't force the bolt home (specifically and AR15)? __________________ Stupidity is not a crime...so you are free to go.

August 27th, 2008, 11:45 AM	#2
dukalmighty VIP Member Join Date: Feb 2008 Location: texas Posts: 3,561	You can either by using the forward assist or removing the upper receiver and pushing the bolt carrier forward with force.One thing you might want to consider is if you run the bullet out that far out of the case it may not fit in the magazine __________________ I like Poetry,Long Walks On The Beach,And Poking Dead Things With A Stick Last edited by dukalmighty; August 27th, 2008 at 01:31 PM.

August 27th, 2008, 04:21 PM	#4
Cupcake VIP Member Join Date: Mar 2007 Location: Michigan Posts: 2,664	Thanks for the $.04. It would seem that even if I can find the "perfect" length this way, they most likely wouldn't feed or maybe not even fit in the mags. Guess I'll make a few small batches centered around 2.260" and stick with that. __________________ Stupidity is not a crime...so you are free to go.

August 27th, 2008, 06:15 PM	#6
Ram Rod VIP Member Join Date: Dec 2007 Location: crawford county, arkansas Posts: 5,206	Just a little more to add. If you are reloading for a rifle chambered for 5.56, I'd recommend sticking with 5.56 brass vs .223. Specific issues concerning the differences in case capacity and pressures have been discussed here before. I hope HotGuns will be along to add his two cents about your proposed activities soon. If all the usual things are in order, I'd stick with your loadbook data OAL as the max, and have a few different sources to review. Here's one from the archives....I'm sure there's more. 5.56/.223 - I just dont get it __________________ RamRod-----sans remords

August 27th, 2008, 08:28 PM	#8
HotGuns Moderator Join Date: Dec 2004 Location: Arkansas Posts: 5,184	There is a way to figure out the maximum length of bullet for the AR. The first thing you need to do is color the bullet as Shizzlemah mentions. Then break open the gun. Remove the rear pin and leave the front pin in place. The reason for this is to remove the spring tension from the bolt, which is too stiff to get a good length. You now have the gun open, place a bullet in the chamber gently. Now take your thumb and gently push the bolt forward. I mean gently. If you do it to hard you will jam the bullet into the rifling and it wont stay in the case. You'll want the bullet to go all the way forward so that the bolt locks and the extractor hooks the case and extracts the bullet. When it does, gently extract the case and catch it with your other hand. The blackened bullet should show some marks where it was engraved by the rifling. Now, with a magazine, check the length of the bullet. Don't insert the bullet into the mag, first lay it along side the follower and inspect it. If it looks like the bullet is too long, forget about long loading your brass, it wont work. It will have to be limited to whatever length will go into the magazine. If it looks like it will go into it without the nose of the bullet running into the front of the mag, go ahead and load it in the mag. Make absolutely sure that it will not run into the front of the mag. Make sure that you have at least enough clearance for the bullet to be able to move some when the rifle recoils, otherwise the bullet will hang up in the magazine when the tip of the bullet is jammed into it. Record the overall length of the bullet and try it. Don't load it to the rifling, load it no less than .010 thousandths from the rifling, to keep pressures down and reliability up. Be sure to go at least 10% less than the maximum load and then you'll have to experiment with the function of the bullet. You can improve accuracy to a point, but there is definitely a place where you lose any advantage due to loss of function. With that being said, it can be done if one is meticulous. What Redneck Repairs posted has lots of merit. Its an AR and it is a battle rifle. It absolutely needs to be 100 %reliable. The chambers are a bit sloppy so that they can endure carbon and residue build up and still function. Any accuracy gain would be minimum as compared to a bolt gun. If you happen to have a barrel with a "match" chamber, you may realize more gain. Match chambers are made to shoot matches, and although they may be more accurate, there is usually a trade off in reliability. The match guns are usually cleaned after each event and see more in the way of maintenance than the standard AR. It will take experimentation to figure out if it is worth the extra step.I have 3 AR's and I don't do it, all of them being accurate enough for me. I do have several bolt guns that I long load for, but they are different animals altogether. In my humble opinion, the .001-.003 that you propose it too short for a semi auto where lots of things are happening beyond your control. A bullet left for any amount of time in a hot chamber can grow longer due to thermal expansion. Also, it doesn't give much room for error and in the event that your bullets are long to begin with it is not unheard of for recoil to actually pull some of the bullets out a bit. Ten thousandths is pretty standard for long loaded bullets and it does give one a larger margin of error when reloading. But all this means nothing if it dosent fit in the magazine. __________________ AR. CHL Instr. To achieve world government, it is necessary to remove from the minds of men, their individualism, loyalty to family traditions, national patriotism, and religious dogmas.' Dr. G. Brock Chisolm

August 27th, 2008, 07:04 PM	#7
Shizzlemah Senior Member Join Date: May 2006 Location: Maine Posts: 724	Seat some bullets to various lengths in trimmed brass, and "color in" the bullet with a sharpie. Chamber them, and the long ones will show rifling marks on the bullets. Go .003-.005" shorter.... BUT you may need to go shorter yet to get a round to run through the mag.

August 27th, 2008, 09:28 PM	#10
HotGuns Moderator Join Date: Dec 2004 Location: Arkansas Posts: 5,184	Good catch Duk...I went back and changed it. The slam fire isnt really the concern though, jamming the bullet in the rifling is. I have had to get a cleaning rod to knock out a bullet that was jammed, then you have to start back at square one. __________________ AR. CHL Instr. To achieve world government, it is necessary to remove from the minds of men, their individualism, loyalty to family traditions, national patriotism, and religious dogmas.' Dr. G. Brock Chisolm

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