243 blowing out primer pockets on reloads

[Esmith]

I wanted to run this issue by the forum. I enherited a hunting rifle from my uncle this summer. Its a Sears Heritage Supreme, mauser action and 24" sporter barrel. I first took it home a cleaned it thoroughly (been sitting in a closet for years). I may be mistaken, but do not think this rifle has been shot much.

I am reloading with once fired Remington and Winchester brass, CCI 200 primers, H4350 and Varget, Nosler 95g Ballistic Tips. I full sized brass and Minimum charges on both powders have blown out the primers. Factory Winchester loads have not blown out on me yet.

Any suggestions and help would be appreciated.

 

[PREMOD70]

My first guess is the brass is sized incorrectly(possible headspace issues), also how many grains of each powder are you using. Do you have a picture of the fired case with the blown primer; several shots at different angles would be nice.

 

[1holeaddict]

A scale check may be what the doctor might order>

 

[fdshuster]

Not enough information provided. How much H4350 are you using? Bullets jumping, touching or jammed into the lands? Are you sure there is no accumulated build-up of carbon in the throat area? If there is, it will raise pressures and be the cause of blown primers. Have you had the headspace checked with Go, No Go and Field gauges? Have you taken headspace length dimensions using factory loads comparing before and after firing lengths? How close is your loaded round headspace length to the as fired lengths? Have you reduced the powder charge ( about 2 grs. less than you are now using) and if so, are the primers still failing? Tried a different primer? And if I kept thinking about it I could come up with a couple more questions.

 

[Esmith]

Working on photos. Rcbs scale has loaded thousands for me without issue. 33g varget and 34 g h4350 blows primes0. Started higher then backed down. Have go gauge and will try tomorrow and take more measurements.

 

[fdshuster]

Checked several loading manuals & your powder charge is certainly well below maximum, then verified that all large rifle primers are .027" cup thickness, so that should be non issues. Firing pin hole in bolt face is oversize (?), but that would not explain factory ammo that is trouble free. I would make it a point to load 5 rounds or so with brass that has been sized, but the headspace length ( I use the Stoney Point/Hornady Chamber O.A.L. gauge to take headspace lengths) kept the same as the fired length. You want to feel just a little resistance when closing the bolt, indicating that the ctg. is locked up tight front to rear in the chamber. A buildup of carbon is possible, but again, why is it not effecting factory loads? Just throwing out some ideas here, like stumbling around in the dark without a flashlight. One of the few times I had ruptured primers the problem was a buildup of carbon fouling. The debris getting into the tuned Rem. 700 trigger also wiped out the trigger resulting in a $70 repair. Cleaned out the carbon with JB, now monitor it closely & no problems. Interesting problem, but I'm sure very frustrating for you.

 

[bheadboy]

your 4350 load is well below factory equilivant, thus, as it is a slow powder, you may be getting detonation, from the lower load.

this does not explain the varget, for headspace if you do not have any of the gages mention, and they are very valuable,
sizing die screwed up andout - take a factory round, place in the shell holder and with the bullet pulled, powder droped, primer pin removed, raise the ram, then slowly screw the siz die down until it touches the case, turn 1/16th more after lowering the ram.

this should be close enough to eliminate the headspace as a major problme.

Bob

 

[AusFclass]

could your fired case lengths be too long causing the chamber to crimp the neck into the bullet?

 

[bozo699]

could your fired case lengths be too long causing the chamber to crimp the neck into the bullet?

Good thought Aus and a possibility too, but my guess would be a severe head space issue. The instructions that comes with sizing dies is ridiculous, there actually dangerous, I mean run die down until it touches shell holder then 1/4 more turn, how precise is that?? the instructions should say Stop if you don't own a good vernier caliper, a small tubing mic and a set of bump gauges,...DO NOT CONTINUE UNTIL YOU DO!!! and maybe the op does I am not picking on him at all I am picking the dia makers for such vague instructions. Esmith if you do own these tools, measure from case head to datum on shoulder on the factory case after it has been fired trouble free in the rifle in question then one of your resized pieces of brass, if there is more then say .005 difference you have die setup issues, back the die out 1/2 turn, resize brass and re measure continue screwing die down a little at a time sizing and checking shoulder bump until you have .002-.003 bump then lock the die down and you should be good to go, best of luck and keep us informed of your progress please
Wayne.

 

[Esmith]

Checked with GO gauge last night and bolt closed without issue. Also compared brass: unfired case trimmed to 2.040, blown primer cases measured 2.045-2.048. Outside neck of blown primer case is .276 ( kind of looks belled in at top). Primer pocket blown out to .311. Will check dies and compare some factory loads tonight.

Thanks again for everyone input.
Everett

 

[WyleWD]

Rcbs scale has loaded thousands for me without issue. 33g varget and 34 g h4350 blows primes0.

Sorry to be a pain on this, but exactly how did you check your scale??

If factory ammo shoots without blowing primers, then your scale is one of the only most likely suspects left. WD

 

[Esmith]

I do not think anything is impossible at this point but calibrated it with the 2-50g weights that came with it. I was actually working on 223 and 308 loads that morning also. I check some loads with balance beam intermittantly. I will say i did not balance the 243 loads. ???

 

[fdshuster]

Closing on a go gauge is normal. Closing on a No Go is a maybe. Just means the headspace is a little longer than SAAMI specs, but as long as you don't push the shoulders back when resizing, the brass will be a good fit for that chamber, even though it's on the long side. All you're doing is fireforming the brass to your chamber. Closing on a Field Gauge is not good, headspace is much too long & case heads could easily be blown off with the first firing. if you don't already have it, get the Hornady Chamber Overall Length tool and take some serious measurements. It also serves the double purpose of accurately determining your bullet seating depths. I would not be without mine, use it constantly.

 

[Esmith]

The fired factory cases are longer 2.050 oal and thicker neck walls, .278 outside with no deformation. Used factory fired case to set die and is really close to by the instruction. Here are a couples pics. Factory on right/bad on left.

 

[AusFclass]

I do not think anything is impossible at this point but calibrated it with the 2-50g weights that came with it. I was actually working on 223 and 308 loads that morning also. I check some loads with balance beam intermittantly. I will say i did not balance the 243 loads. ???

could you have forgotten to change the powder in the thrower?

 

[expiper]

Just had to get inon this one...hahah...the .243 is one of my favs!!!.....I think the rifle is OK>>>>.but something terrible wrong with the re-loads!!!(hows that for insight???)....you said the "trublsom" cases measured 2.050",,,,most SAMMI chambers are 2.055 (I think !!!).....so you are flirting with cases (like Ausie F class warned you of)...that are toooooo long and are crimping into the bullet ,,either ,,,in your seater die which is adjusted for brass that is shorter and is trying to "crimp" the case mouth into a cannulure that is NOT there......or ....jamin in the front of the chamber and doin the same thing........IMHO.....they have been resized by your uncle several times and now need trimmed........Roger
PS...I would get some NEW WW .243 brass and load them and forget about the old ones!!!!!!!
Remeber....if the old cases are too long you can keep reducing the powder chrg till the cows come home and still have over pressure...!!!!

 

[bozo699]

Aus,
Everett said he has tried both H4350 and Varget so at some point he has changed the powder, at any rate they are very close to the same weight of charges, I think 33.0 grains of one and 34.0 grains of the other, both min charges. However as Roger just pointed out your original analogy could be spot on although as I recall Everett said he was shooting new rounds and after the first firing they look fine its the second loading that the problem exists which leads me to believe there is a issue with the sizing process and or as Frank stated a problem with the chamber which still probably falls back to a sizing or loading issue. As Roger pointed out you could be putting on a heavy crimp do to the oal of the case being to long either by the seating die or the maybe short neck of the chamber as this is a old rifle that the op got second hand from a uncle so we don't have any history other then the op's newly found experiences so Everett lets try something, obviously there isn't a issue with first time fired brass so leave your sizing and seating die adjusted where there at for now and resize one case and see if it will chamber with no noticeable difference from a new unfired case then inspect the resized case and see if the end is rolled inward if not proceed to running the case up into the seating die (do not charge or put a bullet in it) just run it in the seating cycle the press and re inspect the case for a rolled effect on the mouth of the case if there is a rolled or crimped effect on the mouth of the case AT ALL then you need to trim as this is your problem and or the seating die is miss adjusted, if this is not a issue then I believe your over sizing at the shoulder so lets do another experiment, neck size the brass only if you do not have a neck die then back your f/l die out about half a turn and resize the case and adjust for about 2/3rds of the neck to be touched (sized) by the die, then charge that case with a minimum charge of Varget NOT H4350 and shoot that round, if there is no issues with the primer pocket and it will extract okay then this was your problem ( over sizing the brass) but if there still is a problem with a blown primer then you need to stop at this point and let a competent smith go over the rifle as it is too dangerous to continue.
Wayne.

 

[PREMOD70]

After all of this and no luck I would try a new can of powder; could be a possible mix of powders IMO. If I was in the same boat I would use IMR 4895 powder, start at 28 grains, continue increasing at 1/2 grain intervals until I got pressure signs; Hodgdon list IMR 4895 at 35.5 grains as maximum. The reason for me is I have more experience with IMR single base powders and trust them more than I do others. If I got pressures at 28 grains then it's time for a through check of the rifle. If no pressures with IMR 4895 then switch back to your favorite powder and have a go at a much lower amount of powder keeping in mind the possibilty of problems with too little powder. I have had 220 Swifts to suddenly blow primers with loads that I felt were safe only to find the barrel erosion was such that backing down the amount of powder was necessary, that may be your problem and if so a new barrel may be in order. Good luck.

PS: the photos of the fired factory rounds showed the bottom left round having more pressure than the others which may be a sign that there is a problem, JMHO.

 

[frnkeore]

I read this whole thread and opening a primer pocket to .311 means that it's WAY off. I don't think case length alone would do and I haven't seen anything else, gun related that could do it, either. It sounds more like something is wrong with the powder.

My suggestion would be to get a can of RL22 or H1000 and start over. Trim the necks .010-.020 (just to be sure), if the once fired will chamber only partial neck size, if not FL size and then expand the necks to .256 and size until they will chamber. With that combo, I can't see where you could get high enough pressure to loosen a primer pocket with a 95 gr bullet.

Frank

 

[Esmith]

I did not mean to mislead anyone. The brass I am/was using is once fired from a different rifle, but I feel I had prepped it properly. Full sized and trimmed. I will try neck sizing the once fired factory cases from my rifle. I will try different powders. I have some IMR 4895. I will check the roll crimp as well. I also plan to reclean the rifle.

I agree with Frank, something is WAY wrong and I'm missing it. I'm kind of worried to fire the rifle again. You can feel in on your face and VERY hard to open bolt when it happens.