25-06 question

ac700wildcat · September 21, 2008, 04:26 PM

I'm working up a load for my new 25-06 and a my load books differ from each other quite a bit on what max load is for the load I'd like to work up. My current load is hornady 117gr btsp bullets and imr4350 powder. My lyman book tells me max load is 51gr, modern reloading says between 48.5 and 48.7, and the imr load information says 52gr. Does someone have another book with data that can confirm 51 or 52 grains being max load and not the 48.5?

I loaded some rounds to run over my chronograph going by my lyman and imr data starting at 47gr and going up by 1/2gr increments up to 51.5. I got only one sign of high pressure, but don't think its actually from being over pressure. Every load I shot cratered the primer. Even two different factory loads get cratered primers. The primer isn't flattened at all and there is no gas leakage. The cases look great too and new primers seat normally and are not loose. I think there is something wrong with my new rifles bolt or firing pin that is causing this. All of the primers looked exactly the same from 47gr up to 51.5gr of powder.

Any answers to my questions are appreciated.

Loader9 · September 21, 2008, 04:48 PM

When working up loads with a specific brand bullet, always default to the bullet makers data. In your case, the latest Hornady data shows 47.1 grs IMR4350 as max. Previous books showed a max of 50.5 grs but with the RN bullet. The RN bullet appears to have more bearing surface than the BT and I'd bet the data has been wrung out by attorneys. I'm sure you checked over at Hodgdon loading center and found data that shows a max load of 52.0 grs. I'd work TO the 47.1 grs and if there are no signs of pressure, work up to the 50.5 grs. Once there and still no signs of pressure, you could work slowly up to the Hodgdon max but as usual, approach any max loads with caution.

**Unclenick** · September 21, 2008, 04:50 PM

Peak pressure depends on the volume behind the bullet after the case expands to fill your chamber. Usually that is looser than the test barrels used to check the loads in the manuals (when pressures actually are checked for them, like the Lyman manual). Also, note that you have to use the same seating depth with the bullet they do for the pressure to match, as well as the same brand of case. That all affects that volume. Then you have to make sure you use the same brand of primer, because that affects how quickly how much powder starts burning upon ignition.

It sounds like the firing pin tunnel in the bolt is too large, or the firing pin is too small, or the firing pin nose is incorrectly profiled. Any competent gunsmith should be able to tell you, but if the gun is new, just call factory service. You can probably send the bolt and a fired case in for inspection by themselves and not have to deal with the high air freight for firearms.

wncchester · September 21, 2008, 05:00 PM

" Every load I shot cratered the primer. Even two different factory loads get cratered primers."

Sounds like your firing pin may be too small for its hole. Unsupported, a "crater" type primer ring can easily form aournd such poorly fitted firing pins even at normal pressures.

You can try a different brand of primers, some have harder/thicker cups and are more resistant to forming those craters than others.

ac700wildcat · September 21, 2008, 05:06 PM

I'll get ahold of remington and see what they say about the problem. I've searched and can't find a contact email so I'll have to give them a call tomorrow.

tommyt · September 22, 2008, 05:16 AM

Remington will tell you it is ok. send it to GRE-TAN rifles and have them check and rebush firing pin hole if needed

September 21, 2008, 04:26 PM	#1
ac700wildcat Senior Member Join Date: September 11, 2008 Location: ND Posts: 239	25-06 question I'm working up a load for my new 25-06 and a my load books differ from each other quite a bit on what max load is for the load I'd like to work up. My current load is hornady 117gr btsp bullets and imr4350 powder. My lyman book tells me max load is 51gr, modern reloading says between 48.5 and 48.7, and the imr load information says 52gr. Does someone have another book with data that can confirm 51 or 52 grains being max load and not the 48.5? I loaded some rounds to run over my chronograph going by my lyman and imr data starting at 47gr and going up by 1/2gr increments up to 51.5. I got only one sign of high pressure, but don't think its actually from being over pressure. Every load I shot cratered the primer. Even two different factory loads get cratered primers. The primer isn't flattened at all and there is no gas leakage. The cases look great too and new primers seat normally and are not loose. I think there is something wrong with my new rifles bolt or firing pin that is causing this. All of the primers looked exactly the same from 47gr up to 51.5gr of powder. Any answers to my questions are appreciated.

September 21, 2008, 04:50 PM	#3
Unclenick Staff Join Date: March 4, 2005 Location: Ohio Posts: 21,063	Peak pressure depends on the volume behind the bullet after the case expands to fill your chamber. Usually that is looser than the test barrels used to check the loads in the manuals (when pressures actually are checked for them, like the Lyman manual). Also, note that you have to use the same seating depth with the bullet they do for the pressure to match, as well as the same brand of case. That all affects that volume. Then you have to make sure you use the same brand of primer, because that affects how quickly how much powder starts burning upon ignition. It sounds like the firing pin tunnel in the bolt is too large, or the firing pin is too small, or the firing pin nose is incorrectly profiled. Any competent gunsmith should be able to tell you, but if the gun is new, just call factory service. You can probably send the bolt and a fired case in for inspection by themselves and not have to deal with the high air freight for firearms. __________________ Gunsite Orange Hat Family Member CMP Certified GSM Master Instructor NRA Certified Rifle Instructor NRA Benefactor Member and Golden Eagle

September 22, 2008, 05:16 AM	#6
tommyt Junior Member Join Date: May 30, 2008 Posts: 3	25=06 Remington will tell you it is ok. send it to GRE-TAN rifles and have them check and rebush firing pin hole if needed

September 21, 2008, 04:48 PM	#2
Loader9 Senior Member Join Date: July 29, 2008 Posts: 949	When working up loads with a specific brand bullet, always default to the bullet makers data. In your case, the latest Hornady data shows 47.1 grs IMR4350 as max. Previous books showed a max of 50.5 grs but with the RN bullet. The RN bullet appears to have more bearing surface than the BT and I'd bet the data has been wrung out by attorneys. I'm sure you checked over at Hodgdon loading center and found data that shows a max load of 52.0 grs. I'd work TO the 47.1 grs and if there are no signs of pressure, work up to the 50.5 grs. Once there and still no signs of pressure, you could work slowly up to the Hodgdon max but as usual, approach any max loads with caution.

September 21, 2008, 05:00 PM	#4
wncchester Senior Member Join Date: December 1, 2002 Posts: 2,832	" Every load I shot cratered the primer. Even two different factory loads get cratered primers." Sounds like your firing pin may be too small for its hole. Unsupported, a "crater" type primer ring can easily form aournd such poorly fitted firing pins even at normal pressures. You can try a different brand of primers, some have harder/thicker cups and are more resistant to forming those craters than others.

September 21, 2008, 05:06 PM	#5
ac700wildcat Senior Member Join Date: September 11, 2008 Location: ND Posts: 239	I'll get ahold of remington and see what they say about the problem. I've searched and can't find a contact email so I'll have to give them a call tomorrow.