Well - How In Blazes Does THAT Work????

Dirk72

Dirk72

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Hey fellas.

I'm stumped. Here's the situation:

I have an M1A in 308 that I load for. I shoot the good ol' 168gr match bullets on 41.5gr of 4895. I load them as per Tonyben on YouTube and other M14 gurus. I have a cartridge gage and all my cases get sized with small base dies, trimmed, and run through that gage before they see powder, bullets and primers. My M1A gobbles them like nobody's business, and feeds and extracts like a Swiss watch. All is cool so far, right?

Now here is where it gets complicated: I bought one of those chit house Rem 700 SPS Tacticals and promptly took the barrel off and put on an 18" Shilen match barrel. The damned rounds won't feed! Sure, ya might be able to chamber a round... but it will take a sledge hammer and a 300 lb. wrestler with road rage to do it! I don't even want to think about extracting a fired case.

Rotten Rod The Gunsmith looked at it a year ago and pronounced the headspace as correct. The gun will cycle prepped empties just fine. Something happens between that and the finished case that makes the damned gun bung up! I've been reloading the simple munitions for 30 years and other than the usual teething problems as a noob - it has been smooth sailing. But this one has me stumped!

Do any of you experts have any ideas? What is going on here???
 
Different rifle, different brass.

Try not to mix semi auto brass with bolt rifle brass. Problem solved.

Why? In a semi, all dimensions can be on the fat side. Yes, you have sized the cases but likely have not bumped the shoulder back far enough... then there is a problem with case stretching and breaking.

So please consider using new brass for each rifle and keep them separated.

Treat each rifle as a completely different entity. Rarely are chambers the same so once fireformed, that brass will not want to change to another chamber.

Good luck

Jerry
 
OP, this is quite basic and I'm sure you've done this but have you checked if your loads are hitting the lands of the match barrel? Do you see heavy engraving marks on the ogive of your rounds?
 
Do you have a comparator like the Hornady one? That will let you measure from the datum line on the shoulder to the case head. Odds are you are resizing your brass enough to chamber in the generous chamber of an M1A but not so much in a match chamber... You probably need to bump the shoulder back some more. Consider getting different brass for the bolt gun or at least a different set of dies unless you want to have to adjust your dies back and forth depending o what gun you are loading for.
 
Mystic Precision said:
Different rifle, different brass.

Try not to mix semi auto brass with bolt rifle brass. Problem solved.

Why? In a semi, all dimensions can be on the fat side. Yes, you have sized the cases but likely have not bumped the shoulder back far enough... then there is a problem with case stretching and breaking.

So please consider using new brass for each rifle and keep them separated.

Treat each rifle as a completely different entity. Rarely are chambers the same so once fireformed, that brass will not want to change to another chamber.

Good luck

Jerry
Click to expand...

^^ THIS ^^

 
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What stumps me is that the OP indicates that sized cases chamber fine in his bolt gun. I'd think that if the brass is undersized in either length or width he would experience some binding with the empty cases. In any event some experimentation with factory ammo would be valuable.

OP - Have you compared the case length from brass fireformed in your bolt gun vs. your reloads? If case length has been eliminated as the problem then I would look into case width issues.
 
OP says 'will cycle prepped empties just fine'....what is considered a 'prepped' empty?
 
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I have been trying to stay away from bullet comparitors, turning case necks, coencentricity measurement and all that jazz - I like my reloading simple and easy - like me! :)

But - looks like I gotta bite the bullet and dive into it. Rotten Rod the gunsmith said the exact same thing Jerry did - and the reason I didn't believe him is that the cases plunk in and out of the cartridge gage slick as snot on a doorknob. I woulda thunk that if the case 'cycles' in both the gage and the gas gun - it would in the bolt gun too!

I will pick up some factory brass, a bullet comparator and do my homework - thanks for all the help boys.
 
Headspace gauges like the Forster simply measure from the face of the bolt to the 'datum' line on the chamber neck. They dont extend into the neck...but a 'prepped' case would. It does sound more like the leade is too short for the bullets you are loading and you need a little more 'freebore'
 
First things first. Use the K.I.S.S. principle.

1. Use a Sharpie to colour the bullet on a loaded round, at the same length setting you've already tried. No powder or primer needed for this step....& maybe even recommended. Make sure you use a case that you've already proven to chamber after sizing & without a bullet.
2. Chamber that round
3. Extract the round. When you extract with a Rem 700 (& similar), pull the bolt back just far enough to get a finger or thumb on the case as it's coming out. Press on the case to keep it centered in the action as best you can through the whole extraction cycle - this will minimize any misleading marks on the Sharpie ink that may otherwise come from scraping across the back edge of the chamber or anywhere on the action. Once there is enough room for the round to clear the action, let the ejector push the round out of the action.
4. Inspect the bullet for marks. If there are marks at the ogive of the bullet (usually look like little squares or rectangles dotted around the ogive circumference), you're jamming that bullet into the rifling.
5. Adjust your seating die to place the bullet deeper into the case until those marks disappear. Use relatively small (.010" or so) steps when adjusting seating depth if you're at all concerned about bullet position relative to the rifling. If you're really not, use bigger steps. Test chamber the round after each step. Make sure to re-colour the bullet - or at least the marks - each time!

So, colour, chamber, inspect, adjust, chamber, inspect. You don't need a comparator to accomplish this. If you're looking for ultimate accuracy and want to get anal about your seating depths, then yes, a comparator is necessary. Otherwise, save your money.

Rooster
 
Ditto^^^
As mentioned many times before, use brass that is specific to that rifle, i.e., don't mix brass between different rifles of the same caliber... All your problems will go away. Much less grief and less work.
 
Given all this discussion of different brass for different rifles it is amazing that there is such a thing as Commercial ammo. It seems to work quite well in the vast majority of firearms and last I checked, you didn't have to specify your caliber/model/make/serial no. when ordering ammo for your firearm. :p

I'm obviously being a little facetious here but unless one's firearms are at the extreme ends of the SAAMI spec. for a specific caliber, I can't see why one would not be able to duplicate a factory round and use it in all your firearms of that caliber.

I think most of the posters are assuming that the OP wants to create high accuracy match loads (and the fact that he's bought a Shillen pre-fit seems to indicate this as well), however his comments are more in the direction of simple utility ammo. If he can develop a cartridge that dimensionally fits his bolt gun there is no reason he can't find a powder/bullet combo that will shoot in both his semi and bolt guns. The ammo probably won't be optimized for either rifle but that's the price for universality.
 
Pr589 said:
Given all this discussion of different brass for different rifles it is amazing that there is such a thing as Commercial ammo. It seems to work quite well in the vast majority of firearms and last I checked, you didn't have to specify your caliber/model/make/serial no. when ordering ammo for your firearm. :p

I'm obviously being a little facetious here but unless one's firearms are at the extreme ends of the SAAMI spec. for a specific caliber, I can't see why one would not be able to duplicate a factory round and use it in all your firearms of that caliber.

I think most of the posters are assuming that the OP wants to create high accuracy match loads (and the fact that he's bought a Shillen pre-fit seems to indicate this as well), however his comments are more in the direction of simple utility ammo. If he can develop a cartridge that dimensionally fits his bolt gun there is no reason he can't find a powder/bullet combo that will shoot in both his semi and bolt guns. The ammo probably won't be optimized for either rifle but that's the price for universality.
Click to expand...

Commercial ammo tends to be made to SAAMI MIN spec... factory chambers vary from min to max... some Semi go into the NATO gauges which are surprisingly BIGGER then what we call commerical spec.

When brass has been fired in a oversized chamber, it grows, takes a set and really doesn't want to get smaller... I am sure you are family with work hardening.

Factory ammo, being virgin brass, has lots of elasticity and simply blows out to fit.... ONCE. The factory never intends you to reload that brass... in fact, they would rather we all stopped.

When you size work hardened brass, it really doesn't want to change its shape. We anneal to try and keep things nice and elastic but there is nothing you want to do to the lower 2/3 of that case... DO NOT TRY AND ANNEAL A CASE HEAD ... BAD KARMA, BROKEN BITS AND MISSING PARTS.

It takes some brass 2 firings... some 3 firings to work harden enough that the case head is very reluctant to change shape. So when you try and crunch a max spec formed case to try and fit into a min spec chamber, it typically doesn't work.

The worst possible thing you could do is make up min spec ammo with formed fired brass to work in a range of chamber dimensions.. especially a big semi. I assure you will see case head separation and a nasty jam.

Two things are happening for sure... his brass is work hardened... his sizing is not enough for a min spec match chamber. Trying to force that case to fit isn't working and if it did, lifespan of that brass would be iffy. I doubt he is loading longer then mag length so likely jamming into the lands is not a problem but always good to check.

New rifle... new brass. In my match rifles, I do use a batch of brass for multiple barrels but my headspace is held to 0.1 thou tolerance and use the same reamer to cut them all. About as near to identical as you can make.

This is not the scenerio that is happening to the OP...

Jerry
 
Dirk72 said:
...The gun will cycle prepped empties just fine. Something happens between that and the finished case that makes the damned gun bung up...
Click to expand...

By this, one should be able to assume that brass can be taken out of the equation....mostly.

Could be he's dealing with thick necks that end up being too big a diameter once a bullet is seated. Or possibly the cases need to be trimmed. I think this last one's a long shot - the OP described his use of a case gauge but did not talk about case length. Maybe that's the gauge and not a Wilson type gauge...? At any rate, an empty case mouth will quite easily swage down into the throat if it is too long - there's an extremely good chance you won't even notice it. But when a bullet is in that neck preventing any radial shrinkage, it will be considerably more difficult to push that case the rest of the way in.

Nothing was said about a pre-fit barrel and who knows what the reamer specs are that his smith used? Is it tight necked? Short throated / no throat? Tighter than typical neck length? Who's to say? How many different variations of .308 are there? I know of a few. His gauges may tell him the headspace is correct but there are a few other dimensions to consider.

All good points regarding case sizing, malleability, prep practices and segregation. Important things to consider, to be sure. However, in this case when the guy makes a statement such as the one quoted above, maybe we need to look at other factors.

Where the heck did he go, anyway? :wave:
 
358R, I took him to mean "new" prepped brass... which lead me to my discussion.

If he was able to get his old brass sized to chamber, then your point is correct... then I would look at OAL .. seating depth.

He would need really really thick necks to not fit in a chamber but then that is something to check as well.

Jerry
 
It's all about the trials of learning about reloading!

The fly in the ointment is the new chamber and old brass and a lack of experience.

I would fully size a case and try it in the chamber using a fully stripped bolt so you can have an accurate feel.

That's the first step... if you can close the bolt on a fully size case you can move on to setting a bullet in that case.

Now if it will not close on that case with the bullet in it, the bullet is seated out too far or the neck diameter is interfering or you have bulged the shoulder of the case by having the seating die set too deep and crimping the mouth of the case when it has no cannalure to engage.

You are going to have to determine these things by experimenting and measuring. You don't need a bunch of expensive gauges. It would really help if you knew the actual chamber/reamer dimensions.

As far as feeding (The damned rounds won't feed!)... is the chamber edge slightly rounded or is it left sharp? It needs to be slightly beveled for the case neck to slide easily into the chamber.
 
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