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Discussion Starter · #1 ·
Okay Guys I have a question, I recently received my SAI M1A back from SA and they replaced the bolt due to some serious pitting well I pitched all my 9X reloaded brass as I believe I had a bad case of primer blow by which caused the damage (Here is a pic)



Well they replaced it with this:



Well I loaded up about 100 rounds with 41.5 of IMR 4895 using a WLR primer and a Nosler 168 CC with a OGL length of 2.260

Well after getting back I looked at the bolt and have 2-3 very small pits in the new bolt (pretty easy to see on a new bolt) so my question is the brass looks fine I had like 3 cases that had some residue around the pocket (will post pic later) but only three total out of the 100.

The brass is all prepped from Scharch and all WCC and LC with the primer pockets uniformed using a Sinclaire uniformer and flash holes have all been deburred, is the 41.5 to hot ? nosler book says 39 is min and 43 max so whats the deal ? I need help cause the next bolt is on me $$
 

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"serious blowby' is right. Question is, Why? A new bolt shouldn't cause problems that quickly. Wow, I'm not sure I could fix this even if I was there. Your load is reasonable. Possibly your primers are defective?
 

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first things first, i would quit having someone else prep your brass. i use a sinclair primer pocket uniformer, on some big hi pressure magnums and dont have issues like that.
how does the primer feel when you seat it, should feel snug, if not pitch the brass.

after more thinking, i think most of your problem lies in how the guy repping your brass is removing the factory primer crimp. i just cant see anything else doing it, and it certainly isnt caused by the sinclair primer pocket uniformer.
 

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Try different brass. Actually buy factory ammo or surplus and see if anything happens. I bet it wont. Common thread is your brass and its probably seen its lifespan. Brass is cheap compared to broken guns and injuries.
 

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Hey Panther, you know my attitude about the WLR primers...well I may have to change my mind about them, it might be the cases rather than the primers.

I bought a new primer seater (the one with the gauge). It is supposed to ensure that the primers are seated to a very consistent depth.

http://www.kmshooting.com/catalog/primer-seater-tools/primer_gauge.html

I've used it with my Lapua brass that has been loaded several times (3-6 times). I wasn't very impressed with the tool because I couldn't keep my primers seated any better than when I used a standard hand seating tool. Then the other day I had to break open a new box of unfired brass. Wow...I was able to keep all my primers seated to within a thousandth of an inch (plus or minus 0.0005"). I always use my Sinclair primer pocket uniformer so I know that the problem isn't uniformity. So I measured the diameters of the pockets of the used brass vs. the new and there was a slight difference, like 0.0005". But it seems like the problem is that the pockets are becoming out of round over time rather than uniformly larger. I can't say when the problem comes up, I will have to run some tests to see if I can identify a pattern but I'm sure that the number of reloads will be the key, I'm just afraid that the number will be less than I prefer.
 

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Discussion Starter · #10 ·
The brass that started to pit the second bolt is only 1X fired, the primers seat fairly snug to me, I have never had issues from Scharch processed brass and I always reprocess the brass 100% by running it thru a F/L sizer and then use a PPU and deburr flash holes

Here are some ok quality pics of the brass, notice 3 have some type of residue and it was only the 3 out of almost 100, I have 50 loaded and have decided to pull them down and going to try drop the load by 1-1.5 to see what happens

A fellow reloader and shooter at the range I go to adv that the primers looked like the had flowed out alittle and suggested I drop the load







I also dropped out some primers of the 1X fired and measured the pockets and came up with a depth of .127" and a diam of .207" which are in spec, the primers are seated below by a few thousands so I know I am seating them deep enough and the primers are from a different lot.

I am at a loss, surely the SAI bolt cannot be defective ? I have reloaded for over 2 yrs and reload for a bolt gun and had a DPMs .308 and a STG 58 and never had bolt issues like this I am about ready to jump off a bridge trying to figure this out
 

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Look at the cratering of most of your primers. Either you load is to hot for your gun, or your primers are too soft, the firing pin has to much protrusion or the primer hole in the bolt is too big, are some possible causes.

I would try some of the CCI # 34 primers first, ang then if you still see primer cratering I would lower the load...

What happens when you shoot Federal Factory 168gr Match???

Or some kind of Military ball.
 

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i guarantee you it is not the bolt. do you know how the primer crimp is being removed from the brass? you do show a touch of hi pressure or oversized firing pin hole, but neither of those is the cause of the leakage around the primer.
 

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Your load is a standard "known good" load. My QuickLOAD software even says that it is a nice pressure, probably around 47,000 PSI so that means that there is a mechanical issue, by that I mean something don't fit right. Those gas jet marks on the head of your cases are excessive as far as I'm concerned. In fact it looks to me like the primer pocket has a little flame cutting on a couple of those pieces of brass.

Does this happen with any other brand of ammo?

If not, then all it can be is the brass or the primer. If the brass has less volume than is normal for WCC or LC then that would raise the pressures. So buy a small number of new Winchester cases and use your WLR primers and a moderate load of powder (your 41.5 gr load would be fine) and see if you still get those gas marks on the head of the case. If they go away then the brass was the problem. If you still have a problem then buy a small quantity of other primers and test them in the Winchester brass. If the problem goes away at that point then we know it is the primers.

I just had a thought, since your photo only shows three cases with powder burns, then that means that the majority are not failing, so the problem is not a consistent issue of case or primer size. It's an issue that is intermittent, not a common thing. Do you tumble your brass? If so then check the inside of your cases after you tumble them and see if there is any polishing medium left inside. I had that problem for a while and it would cause my case volume to be less and that increased my chamber pressure, in some cases by quite a bit.
 

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Discussion Starter · #14 ·
I do tumble my brass and I have a universal decapper in station #1 on my press to clear any media stuck in the flash hole during loading, my buddy at the range said just because 41.5 is a pet load the rifle i have may be alittle different and require a lighter load he suggestion was to drop the load by 10% or go to the minimum listed for that bullet which Nosler has a starting load at 39.0 and work up to a decent load below the 41.5 I am happy with and after 3-4 reloads pitch the brass, the bolt was all new from SAI for the most part (replaced bolt body, extractor and bolt roller and clip) and set HS at 1.632"
I have taken the brass with a seated primer and tapped it at a angle pretty hard and don't see or measure the primer backing out, as far as removing the crimp from the pocket I believe Scharch reams them but if they were doing a crappy job they would not be in business and I cannot find anywhere where people have complained about there brass prep, I do have a few hundred Fed 210's to try but after they are gone all I have are 10K + WLR to burn thru.
The firing pin looks and feels very smooth and does not look bad but then again I have no idea what to look for, i don't have any other brass except the 1K mixed WCC and LC 1X from Scharch so I may swap out some primers and lighten the load by 10-15% and see what happens, I am getting a decent seal around the mouth with a dark even ring, and the firing pin hole look tight so i am at a loss.
 

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The primers don't look all that bad. I had some leaking by due to pressure and they were much much worse (flattened to the point of mushrooming and cratered). With my LC90, the brass starts to flow and the headstamp gets ironed out before I get any gas leakage. But even then I wasn't getting those big blown out pits like I think I see in your photo.

I would guess there's something going on with the brass or the primers. How much are you taking off when deburring? How are you spinning the uniformer? My guess is that the pockets were compromised.
 

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Discussion Starter · #16 ·
I took the remaining 60 rounds and pulled the bullet using a kinetic hammer (what a PITA but it's all I have) anyway I derpimed them and some of the primers came out very easily so I pitched them and the remainder of the 100 from the last of the box, my plan is to seat some new primers in station one of my press and if they seat to easy I am going to pitch the brass or at least examine the pocket my next step is to drop the load by 10-15% and see what I get as Nosler lists the min load at 39.0 for a vel around 2450 using a 168 CC pill but there not using milsurp brass either.
 

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Panther308,
I am a big fan of hand held primer presses. They will give you a better feel when seating primers. You may want to try CCI BR2 or Wolf large rifle primers(not the magnum). They have a slightly larger diameter than the WLR primers.
My only other question is, do you crimp your bullets after seating them?
I say that because any inconsitancy in case length may result in higher case pressure.

Glenn
 

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Discussion Starter · #18 ·
Panther308,
I am a big fan of hand held primer presses. They will give you a better feel when seating primers. You may want to try CCI BR2 or Wolf large rifle primers(not the magnum). They have a slightly larger diameter than the WLR primers.
My only other question is, do you crimp your bullets after seating them?
I say that because any inconsitancy in case length may result in higher case pressure.

Glenn
Glen,

I have dillon dies and they seem to be very consistent on seating, I measure off the ogive and after I give a small crimp (.002) in station #4 (Taper crimp) I have a very consistent OGL at 2.260".
I loaded up another 50 cases using a totally different batch of WLR primers and they seemed to seat fairly snug but I did manage to cull out a few that were pretty loose ( was able to push a primer in 1/2 way with my thumb) and I also went with a reduced load of 39.5g of IMR 4895 and plan on taking these out next week to see how they do, I figure as long as there is no residue on or around the case head and the primers don't look cratered and I have a good seal mark around the mouth I should be good and if I have trouble i may scrap the 150 cases of WCC and try the LC ones I have in a bag, they are also from Scharch but bought last year.
After I manage to go thru these my plan is to just buy new unfired brass like some IVI and use the pittance i get from recycling this brass to offset the cost...no I don't have ton's of $$$ but I am learning very quickly that buying brass prepped may not be the way to go or maybe I just got a bad batch or over prepped it myself...live and learn
 

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Looks like some primer holes were too loose and or were not seated correctly thats all.When taking out the crimp it does not take much to make the primer holes too loose,use good qulity tools.I use Dillon Super Swage or just don't use military crimp ammo. you will get more reloads. Scharch does a good job in removing the crimp, I noticed that when I prime their brass its easier to seat the primer. My swaged primer holes feel tighter and I have not had any issues with leaking.
 

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Panther308,
Ogive measurement will not have any effect on the bullet crimp. I am concerned about the case length. If your crimp is set for a 2.005" case length with a .002" crimp and a 2.007" case gets in there you have a .004" crimp. that will cause increased case pressure.
I do agree that the processed brass in combination with the WLR primers are the catalyst to this problem. I am trying to think what other variables are contributing to this.

Glenn
 
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