Sako 6mmppc USA Problem

[manitou210]

Just got a very nice condition Sako 6mmppc heavy barrel single shot.
Came with 50 fired Sako Brass and 40 new brass.
I neck sized brass and loaded some 65gr V maxs and 70 gr Sierras using H 322 powder.smallest group 5 shot was .250" with V max and 70 gr sierras
When I close bolt its quite stiff closing, fired brass not loaded is stiff closing.New brass is smooth as well as fired brass full length re-sized.
I looked at chamber with bore scope, seems smooth and no marks.
There are no marks on brass after cycling in chamber.
Whats your thoughts



manitou

 

[JohnHenry]

As your full length sizing corrects the issue, you may want to get a full length bushing style sizing die and size after each firing bumping the shoulder .001" to .002". If the sizing die is only slightly tighter than your chamber, you will not over work your pricey brass. Thus, I would suggest Harrell's but do not know if they ship to Canada. Redding also an option.

http://harrellsprec.com/index.php/categories/reloading-dies

PS: How much H322 are you using?

 

[LHSmith]

COAL too long?......are the fired cases from THAT gun?....... After brass is fired in a chamber it is normal to have some resistance closing the bolt....the hotter the load -the more resistance, and Sako brass is soft. Sooner or later your going to have to FLS, why not just FLS every time and get optimum accuracy that FLS affords, and save your bolt lugs from abuse.

 

[BoydAllen]

It seems that you will need to be FL sizing every time. This has been standard practice in short range benchrest for some time. As to your tightness after firing issue, I think that the SAKO brass that you are using may be softer than the Lapua that is popular for competition these days (and which has been for a long time). This brings up the issue of how hot your loads are. As you probably know, accuracy is usually found at more than one charge weight (or volume). These sweet spots, or nodes, are generally evenly spaced. I would try to find one at a lower charge, perhaps around a grain less +-. Not being familiar with your chamber, I cannot say whether fire formed and possibly neck turned Lapua brass would work for you, but it might be worth investigating. I would start by measuring the back of your new and fired brass and comparing the top edge of the extractor cut diameter of Lapua .220 Russian brass.

 

[JRS]

COAL too long?......are the fired cases from THAT gun?....... After brass is fired in a chamber it is normal to have some resistance closing the bolt....the hotter the load -the more resistance, and Sako brass is soft. Sooner or later your going to have to FLS, why not just FLS every time and get optimum accuracy that FLS affords, and save your bolt lugs from abuse.

+1

 

[Dusty Stevens]

You need a redding 6ppc USA fl die for that chamber.

 

[Fire306]

Looks like your loads gave you some good accuracy after we shared some load data.
My PPC reloading regime is, Body size (redding body die) to bump the shoulder .001" or less.
Next, Neck size and de-primer with Wilson Hand Die, clean primer pockets, prime cases, charge with powder (each load measured), seat bullets.
The tight bolt close would indicate to me that the brass wasn't sized properly for that chamber, neck sizing doesn't move the shoulder back at all which is likely the cause.

 

[Keith Kilby]

Manitou....I just got "same rifle" recently and shot it for the first time yesterday. Mine is an "A" prefix version. I started with new Norma brass and a Whidden FL bushing die, 0.265" bushing and had no issues. 4 groups fired averaged 0.260" with best group at 0.215"......this was while doing an OCW test. Great little rifle....you're going to love it.