Pressure in a new tikka

[T28w]

Ok guys. Need some input now.

Went to range. Using Barnes recipe of min load of 62.4 and max over 69 of h4350. Barnes 168 ttsx. Cci mag primer 250, Norma brass never fired. Loaded up a ladder test.
New never fired tikka t3x 300 wsm.
Loaded a couple at 64 gr for sighters.

Had a very heavy bolt lift and what appears to be extractor mark. Shoot another and pretty much same result. So i stopped and dropped back to to lowest charge I loaded which was 63 even. Pretty much the same bolt lift, maybe slightly better. Went ahead and shot the 63.7 loads and then a 64 or two to end. If almost felt like it was getting a better bolt lift but still signs of a extractor swipe.

Chrono is measuring 2950 with 63 gr. And 3000 and just above with 63.7 and 64.0 gr.
Barnes recipe is 2847 with 62.4
And 3126 with 69.4.

I know my seating depth is slightly inconsistent but I’m very sure of my measurements to lands. Verified it 3 diff days and always getting within a couple thousands each time with a modified case (Norma from copper creek) and hornady lnl gauge.

Thoughts?
25165AB1-29F9-4449-8092-1FE50FA8441B.jpeg DB4AE229-EDBB-4F0F-B550-243A313556AA.jpeg

 

[T28w]

This was also in the inconsistent seating depth thread but wanted a new thread for this.

 

[Lawnboi]

Is the gun new? Did you clean it? How much is your brass growing?

 

[Rifles And More]

Those are pressure signs.

Norma brass has a reputation for being on the soft side.
Hodgdon lists 61min to 64max. Not sure how that jives with the Barnes bullets data. I'd clean the rifle really well. Back off to the 61 charge and see what happens there.

 

[T28w]

Is the gun new? Did you clean it? How much is your brass growing?

Yes, yes, and I don’t know yet.
The first three shots were 63.0
Next three were 63.7 and the 64.0 for the rest.
Accuracy was very good on the 63.7and 64.0 and am ok with velocity although a little more would be nice, it will do fine for my ranges.

 

[Lawnboi]

How many rounds? Iv had a couple rifles that showed pressure for the first few boxes. I’d hate to be trying to develop a load on a fresh barrel.

 

[brn2hnt]

I’ve seen pressure with factory loads when there was any amount of grease/hoppes in the chamber.

Dried it all off and back to normal. Worth checking out.


Sent from my iPhone using Tapatalk

 

[T28w]

I agree. Not really “developing” a load. Just trying to get rounds down it. I have seen any factory ammo in god knows how long for a 300 wsm. So I was loading some up just to shoot and possible have an idea of what I was going to get. Prob going to leave what I’ve loaded and load more at 62-63 and see what happens with next 10-20 rounds.

 

[SouthPaw]

This happened to me recently with a brand new tikka .243 I bought for my wife. First 5 rounds down the tube, factory federal ammo, showed pressure on the case (ejector swipes). I cleaned it and proceeded to put 50 rounds down the tube during barrel break in and now the same ammo shoots <1" and shows no pressure. I am just now starting load development with Hammers using the fired brass.

 

[Hnttillmt]

Does seem strange. Maybe you just got a tight chamber . As others have said, I would give a very good scrubbing to your bore and hope things improve. I’m shooting pretty much the exact same load in the same rifle. Only difference is Winchester brass. Off the top of my head I believe I’m 68 and change on the h4350. It is a hot load clocking in at 3150 but it’s damn accurate and I’ve been shooting it for quite a few years. It’s a deadly combo.

 

[TraderMike]

Does seem strange. Maybe you just got a tight chamber . As others have said, I would give a very good scrubbing to your bore and hope things improve. I’m shooting pretty much the exact same load in the same rifle. Only difference is Winchester brass. Off the top of my head I believe I’m 68 and change on the h4350. It is a hot load clocking in at 3150 but it’s damn accurate and I’ve been shooting it for quite a few years. It’s a deadly combo.

Is this a compressed charge in your load?

 

[Hnttillmt]

Nope. Can’t remember what my coal is off the top of my head but I seated just deep enough to fit in the magazine.

 

[T28w]

Is the gun new? Did you clean it? How much is your brass growing?

Just had time to sit down and measure. Brass is growing .008

 

[T28w]

Those are pressure signs.

Norma brass has a reputation for being on the soft side.
Hodgdon lists 61min to 64max. Not sure how that jives with the Barnes bullets data. I'd clean the rifle really well. Back off to the 61 charge and see what happens there.

 

[T28w]

Nope. Can’t remember what my coal is off the top of my head but I seated just deep enough to fit in the magazine.

Are you in a factory mag ?

 

[T28w]

Also, since case capacity affects pressure, if this brass grew 8 thousandths and I bump it 2 back, has the case capacity increased of any significance to create less pressure?

 

[Vern400]

Ok guys. Need some input now.

Went to range. Using Barnes recipe of min load of 62.4 and max over 69 of h4350. Barnes 168 ttsx. Cci mag primer 250, Norma brass never fired. Loaded up a ladder test.
New never fired tikka t3x 300 wsm.
Loaded a couple at 64 gr for sighters.

Had a very heavy bolt lift and what appears to be extractor mark. Shoot another and pretty much same result. So i stopped and dropped back to to lowest charge I loaded which was 63 even. Pretty much the same bolt lift, maybe slightly better. Went ahead and shot the 63.7 loads and then a 64 or two to end. If almost felt like it was getting a better bolt lift but still signs of a extractor swipe.

Chrono is measuring 2950 with 63 gr. And 3000 and just above with 63.7 and 64.0 gr.
Barnes recipe is 2847 with 62.4
And 3126 with 69.4.

I know my seating depth is slightly inconsistent but I’m very sure of my measurements to lands. Verified it 3 diff days and always getting within a couple thousands each time with a modified case (Norma from copper creek) and hornady lnl gauge.

Thoughts?
25165AB1-29F9-4449-8092-1FE50FA8441B.jpeg DB4AE229-EDBB-4F0F-B550-243A313556AA.jpeg

Case lube remaining will do that for sure. Sierra Tech Support helped me out with some 7.62 bolt gun issues the brass extruded into the extractor hole at normal pressures.

 

[Gasman]

I'd try bumping the shoulders back a bit, even though you're using new brass. If that eliminates the pressure signs, you probably have a tight chamber and should measure the headspace.

 

[wind gypsy]

Just had time to sit down and measure. Brass is growing .008

Total length or to a datum on the shoulder? If to the shoulder it’s definitely not short on headspace.

 

[wind gypsy]

I’ve found lately that fired brass frequently builds pressure quicker than virgin even if the case is a little bigger.