I might have a problem?

[LOUD]

My Daughter and I decided to load some 7mm Rem Mag Ammo and go to the range. We took brand new Winchester brass , cci Lr mag primers and 57 grains H4831 behind a btsp 175 gr projectile and we fired about 4 shots and quit ! The gun is a beautiful custom mauser , the rounds chambered well and when we fired the bolt was tough to raise and very tough to bring back to the open position . I had to tap the bolt back with a wooden mallet . A couple of the primers blew out and the case heads are flattened and primers cratered , thats when we stopped shooting. I happened to have a few factory rounds and we tried those , no sticky boltor other problems. So my question is , did I use too much powder ? . My load data said starting load at 55gr and max load at 58 gr Just glad we had no Kaboom!!.your opinions appreciated.................LOUD

[mehavey]

7mm Rem Mag ... 57 grains H4831 behind a btsp 175 gr ... bolt was tough to raise ...had to tap the bolt back with a wooden mallet... primers blew out and the case heads are flattened and primers cratered ...

7mm Rem Mag
175 Sierra SPBT
H4831/57.0gr (That's Sierra's starting load)

I find it VERY hard to believe that load produced more than 42,000psi -- waaaaay low pressure for a 61,000psi-rated cartridge.

Go back and look very carefully at the powder (is it really H4831? -- is there any possibility it was H4895?), and at the bullet (is it really a 7mm/.284?), and pull a bullet/weigh the charge (any chance it is 67 grains? [it will fit])

And what scale are you using?

.

[603Country]

Do you have IMR4831 instead of H4831? That'd give you higher pressure, and I did just that with my 270 some years back (used the H4831 max powder charge, but used IMR4831 instead). I didn't get the more extreme signs of pressure like you did, but it was very obvious that I had messed up. I don't have any of my loading books with me right now, so I don't know what the max would be with the IMR powder. Still, that sounds like more of a problem than the faster IMR powder would cause.

I'd go back to basics and check every last little thing out - OAL, neck wall thickness, and on and on.

[mehavey]

IMR4831 (instead of Hodgdon) still wouldn't get the OP out of the low 50's pressure.
Something else is afoot here.

[mrawesome22]

There is a reason they said to start at 55. You have found it.

[ScottRiqui]

There is a reason they said to start at 55. You have found it.

There's almost certainly some other factor in play here. As mentioned earlier, according to at least one manual, the 57 gr weight the OP was using *was* a recommended starting load.

[mrawesome22]

Yep, and that factor may be a tight custom chamber.

The book he has said start at 55 and he didn't.

[LOUD]

hey guys its really h4831 and I was using a hornady digital scale that had been calibrated with a check weight . I havent weighed a bullet yet or measured one for the correct diameter. I just ordered a bullet puller and as soon as it gets here Im dumping and weighing . but something is unusual here. we have a tollerance of .1 grains either + or- which we checked every single powder drop.Daughter is powder trickler ! lol.......still scratching my head ........LOUD

[mehavey]

It probably wasn't a book so much as likely the IMR site which uses a 175Nosler partition -- and well within reasonable margins.

Something else is happening here to get symptoms associated w/ 80,000psi


Put that 175gr bullet (or better, any 50-ish 223) on that Hornady scale see what it weighs

[ScottRiqui]

The book he has said start at 55 and he didn't.

Well, that comes down to the luck of the draw as to which reference he used, doesn't it? When you're working up a new load, do you consult dozens of different references and use the absolute lowest recommended starting load you can find?

If he had used Sierra's data, then the 57 gr he used would have been the recommended starting load - would you still be harping on him simply because there's some other source that lists one that's lower?

[chris in va]

My Lyman manual has 53.7-60.0 listed for 4831.

I think you need to measure that powder charge with a beam scale.

[Sport45]

I would have stopped shooting after the first round indicated something was wrong...

I agree with the others. Is there a chance you used the wrong powder?

You don't have to wait for the puller to break them down. Remove the die from your press. Put the cartridge in the shell holder and run it up. Wrap some electrical tape around the jaws of a pair of pliers and use them to grab the bullet above the press and then lower the ram. You might (or might not) ruin one bullet, but all the powder will still be in the case for inspection and weighing.

[dacaur]

If he had used Sierra's data, then the 57 gr he used would have been the recommended starting load - would you still be harping on him simply because there's some other site that lists one that's lower?

Yes if he wasnt using sierras bullets.....

I always check the bullet and powder MFG for reference first, and go from there. I use mostly hornady bullets, and hornadys starting loads are normaly lower than the powder MFG's loads, so I start there.

Assuming his bullet MFG doesnt have load data, hodgton lists the starting load at 55gr and the MAX load for H4831 at 58Gr.

Yes, he should have started at 55gr, unless he is using sierra bullets....

[mrawesome22]

Scott, I would be advising him to reference more than one source if all he had was the Sierra manual.

BTW, data.hodgdon.com ....... Start load 55gr.

I don't trust one source for info. I've seen too many typos to trust just one source.

[ScottRiqui]

I agree in principle, but the opposite can happen as well - "analysis paralysis". How many times have you found two references where the starting load in one was above the max load listed in the other? I guess you could do what I mentioned earlier - stock an entire bookshelf full of load manuals, check every one every time you're working up a new load, and always default to the lowest of all the listed starting loads. I guess you'd have to do the same thing at the high end - find the lowest max load among all the manuals and stay under that.

"A man with two wristwatches is never certain what time it is."

[math teacher]

You need to eliminate variables. Pull a few bullers as suggested above and weigh them. They should weigh within about a grain of 175. If so your scale is OK. If not then you either have a bullet problem, or the scale is wrong. If OK weigh the powder to see if it is actually 57 grains. If it is, I also suspect the wrong powder.

[243winxb]

Too much powder for the bullet type? The construction of the bullet, length of bearing surface, jacket thickness, core hardness all effect pressure. When the cartridge first became available in 1962, difference in barrels was a problem. Some just produced more pressure than others. Lowest starting load found is 53.7 gr of H4831

[mehavey]

Lowest starting load found is 53.7 gr of H4831...

What bullet make/manual is that from?

The OP noted that he re-checked w/ Factory 7mmMag, which is usually loaded to maximum performance just barely short of 61,000psi. If the rifle had no problem w/ that, it's more likely a hand-load anomaly.

`Waiting to hear back from the OP on that.... (as well which specific bullet he used)

[Pongo]

I presume you do size your new brass and check case length. I have had new brass that needs trimming.

[LOUD]

well , I did size them but I didnt check the case length .One evening this week Ill pull some apart and weigh and measure everything and let you folk know what I find . Thanks for all the inputand check back on this thread ...........LOUD

[Jimro]

Did you trim your brand new Winchester brass before you loaded? If the brass is long it could "pinch" the bullet and cause a pressure spike.

Jimro

[603Country]

I'm thinking the same as a couple of ya'll are...maybe the bullet isn't getting released from the case neck. From a list of what the problem probably isn't:
- Primer was the right one
- Powder appears to be the H4831
- 7MM bullet in 7MM rifle, so probably Ok there
- factory ammo shoots (I think he said), so the rifle is Ok

Now, if we do assume that the bullet is the correct weight (which the OP can read off the box), we are running out of possibilities. Is he seating the bullet really really deep? Probably not. I think that leaves us with case neck issues. Either the case is way too long or the case wall thickness is too much for a tight custom chamber.

I'd take a factory round and a handload and sit em side by side and measure them in every possible direction and compare the results. Something is wrong with the handload, and if it's not the powder, I think it's the case. Gotta be.

[Jim243]

the rounds chambered well and when we fired the bolt was tough to raise and very tough to bring back to the open position

My guess is it is the scale not the case. Definately high pressure load, but why???

Jim

[SHR970]

Was this from a new batch of powder?

The distributors have been known for accidently putting the wrong powder in the bottle from time to time. If it is from a new container, I would be on the horn to Hodgdons with the lot number in hand and let them know you may have a problem.

[Sure Shot Mc Gee]

My load data said starting load at 55gr and max load at 58 gr

Using Hodgdon powder is a personal choice. But not necessarily the right one? If I had such a problem not knowing what the cause? 1.--I'd dump out the powder!! 2.--check & reset my scale. 3.--mic my bullets for caliber. 4.-- buy a new pound of IMR 4831 instead.---I have 2-Hornady manuals a Spear and a older Lyman for reference only that I've been looking at tonight in your behalf. All current manuals suggest the use of IMR-4831 and not the slower burning of the two >H-4831. Questions you have to ask yourself? Your loading data is correct and up to date? Can you really trust that powder? &/or bullets you were using were they actually 28 caliber? Just like the other posts. >"These are my thoughts on your event LOUD."<