25-06 blown primers

[Dmerritt47]

I have been trying to find a new load for my 25-06 and was loading 110 eld-x as well as Berger 115. Both loads were using h4831sc. Hornady says max load for a 117 gr bullet with 4831sc is 54.7 gr. When I loaded the bergers with 53 gr of 4831, I was blowing primer pockets. I had a 10 shot load to see speeds and group and shot 7, 8, and 9, blew the primers so I did not shoot the last round.
My question is, is there another reason that I might be blowing primers other than over charging the powder? The eld-x bullet shot fine even up to 55 gr of 4831. Any help or suggestions would be appreciated!

 

[Taudisio]

What primers does the book list and what ones are you using?

How many firings do you have on your brass?

 

[WKR]

There are plenty of reasons. You could be jammed way into the lands causing over pressure, you could have a massive carbon ring causing a spike in pressure....
Did you measure the base to ogive length on the new bullet and compare it to your chamber length?

 

[Dmerritt47]

What primers does the book list and what ones are you using?

The book says Winchester WLR primers and I used fed 210 on both loads.

 

[Dmerritt47]

There are plenty of reasons. You could be jammed way into the lands causing over pressure, you could have a massive carbon ring causing a spike in pressure....
Did you measure the base to ogive length on the new bullet and compare it to your chamber length?

I measured my BTO on the lands and both the eld-x and the bergers were 3 thousands off the lands. The barrel shot count is at 250. I cleaned the barrel prior to the load development and have cleaned every 50 to 100 rounds prior to that.

 

[wind gypsy]

What brass are you using? Could have less capacity.
You're using H4831 not IMR?
Could be faster lots.
Could be a chamber/barrel issue.
Could be partially all of the above.

3 thou jump is definitely going to be higher pressure than book COAL.

 

[TaperPin]

That’s a lot of shots in one go - did 7, 8, & 9 sit in the chamber getting hot?

 

[Dmerritt47]

What brass are you using? Could have less capacity.
You're using H4831 not IMR?
Could be faster lots.
Could be a chamber/barrel issue.
Could be partially all of the above.

3 thou jump is definitely going to be higher pressure than book COAL.

I uses hornady brass. (The same as book suggested) And definitely h4831sc not IMR.
Can you help me understand why I would have more pressure from a longer COAL and the short jump to the lands?

 

[Dmerritt47]

That’s a lot of shots in one go - did 7, 8, & 9 sit in the chamber getting hot?

I shot the rounds in 5 shot groups with a full barrel rest in between each 5 shots. I was single feeding the rounds but never more than a few seconds in the chamber before I shot them.

 

[wind gypsy]

I uses hornady brass. (The same as book suggested) And definitely h4831sc not IMR.
Can you help me understand why I would have more pressure from a longer COAL and the short jump to the lands?

Close to lands, the bullet meets resistance almost immediately upon ignition so pressure climbs faster. That isn't the sole reason for your woes though IMO. You can usually go well over SAAMI max and not pierce primers. Check your firing pin to make sure it isn't damaged and a bit sharper.


Also, hodgdon says 52.0 is max with H4831 w/ a 117 hornady SPBT and my old berger manual says 54.3 max with their 115 for what that's worth.

Make sure your chamber is clean/dry and I'd back off from the lands and back down on charge a bit.

That lot of bergers could be a little thicker and build pressure faster too.

 

[Dmerritt47]

Close to lands, the bullet meets resistance almost immediately upon ignition so pressure climbs faster. That isn't the sole reason for your woes though IMO. You can usually go well over SAAMI max and not pierce primers. Check your firing pin to make sure it isn't damaged and a bit sharper.

View attachment 763714
Also, hodgdon says 52.0 is max with H4831 w/ a 117 hornady SPBT and my old berger manual says 54.3 max with their 115 for what that's worth.

Make sure your chamber is clean/dry and I'd back off from the lands and back down on charge a bit.

That lot of bergers could be a little thicker and build pressure faster too.

Sweet! Thanks for the info.
I also have wondered about using large rifle magnum primers in my loads but I'm not sure what that will do to pressures or to faster or slower powders. Would that increase my pressure as well?

 

[TaperPin]

I have been trying to find a new load for my 25-06 and was loading 110 eld-x as well as Berger 115. Both loads were using h4831sc. Hornady says max load for a 117 gr bullet with 4831sc is 54.7 gr. When I loaded the bergers with 53 gr of 4831, I was blowing primer pockets. I had a 10 shot load to see speeds and group and shot 7, 8, and 9, blew the primers so I did not shoot the last round.
My question is, is there another reason that I might be blowing primers other than over charging the powder? The eld-x bullet shot fine even up to 55 gr of 4831. Any help or suggestions would be appreciated!

 

[jjohnsonElknewbie]

 

[Dmerritt47]

Ok ill back the load down and see if that changes things. Guess this just shows that there is only one way to find a certain guns max because I now have two sources that show a max over 54 and 2 that show a max under 53. Thanks for the help.

Any suggestions on what a large rifle magnum primer would do to pressures or faster or slower powders in a 25-06?

 

[jjohnsonElknewbie]

Ok ill back the load down and see if that changes things. Guess this just shows that there is only one way to find a certain guns max because I now have two sources that show a max over 54 and 2 that show a max under 53. Thanks for the help.

Any suggestions on what a large rifle magnum primer would do to pressures or faster or slower powders in a 25-06?

I've heard on here that one should subtract .5-1 grain from standard LRP load if using a magnum primer. YMMV.

 

[pbroski]

Ok ill back the load down and see if that changes things. Guess this just shows that there is only one way to find a certain guns max because I now have two sources that show a max over 54 and 2 that show a max under 53. Thanks for the help.

Any suggestions on what a large rifle magnum primer would do to pressures or faster or slower powders in a 25-06?

Good plan! Out of curiosity. What were the velocities of the loads with blown primers?

 

[Koda_]

Magnum primers can increase pressure, should back down and work back up. .003" is way too close to the lands, most people have about a +/- .002" tolerance on how much they squeeze calipers, you could easily be actually touching the lands. I start all my load development .020" off the lands.

Before I do a charge weight test I run a pressure ladder starting well below max, one shot each charge weight recording velocities until I get the first hints of pressure. Then I know exactly where my max charge weight is with my components and powder, and also know if safe charge weights will give me the velocity I want. Once I run a pressure ladder I begin the optimal charge weight testing to find which charge weight gives the best groups and fine tune from there, if needed.

 

[Dmerritt47]

Good plan! Out of curiosity. What were the velocities of the loads with blown primers?

I got an average of 3160 with and SD of 17 on those 9 but the three that blew the primers were 3173, 3190, and 3166.

 

[Dmerritt47]

Magnum primers can increase pressure, should back down and work back up. .003" is way too close to the lands, most people have about a +/- .002" tolerance on how much they squeeze calipers, you could easily be actually touching the lands. I start all my load development .020" off the lands.

Before I do a charge weight test I run a pressure ladder starting well below max, one shot each charge weight recording velocities until I get the first hints of pressure. Then I know exactly where my max charge weight is with my components and powder, and also know if safe charge weights will give me the velocity I want. Once I run a pressure ladder I begin the optimal charge weight testing to find which charge weight gives the best groups and fine tune from there, if needed.

I was mixed up on my length. I started this thread while I was at work and just re-measured when I got home and the bullets are actually .02 off the lands. My lands measurement is 2.698 BTO and the bullet measures 2.678 BTO.

 

[Koda_]

I was mixed up on my length. I started this thread while I was at work and just re-measured when I got home and the bullets are actually .02 off the lands. My lands measurement is 2.698 BTO and the bullet measures 2.678 BTO.

Then the only thing I can think of is your over charging. From the comments above load data I would run a pressure ladder starting at 49gn, work my way up in 1/2gn increments till you find the first hint of pressure... should be below the 53gn charge weight you already know. Its good to know where max is especially with temperature sensitive powder and stay at least 1/2gn charge weight away from first hint.
Lets say its 52gns, then I would run a charge weight test around 51gn in .3 increments on either side looking for best groups.

I personally would consider a different powder for more velocity if you have some on hand. Otherwise Im guessing you will land around 2850/2900 fps.