6.5 Creedmoor hard bolt lift

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diegocn

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I was working up the load for 6.5 Creedmoor.

The rifle is a Savage 10 action with a 22" barrel from Savage Axis. Head space is checked and the bolt will not close on the no-go gauge.

The load data is as follow:
Brass: Sako 6.5 Creedmoor
Primer: Dominion LR
Projectile: Hornady .264 140 Gr BTHP
Powder: 6.5 Staball
COAL: 2.822"

Hodgdon data called for 40.0~44.0 Gr of 6.5 Staball, with 2535~2806 fps out of a 24" barrel.

When I get to 42.5 Gr of charge I started noticing bolt lift becomes hard. At 43.3 Gr the bolt lift becomes quite stiff that there's definitely something not right about it. So that's where I stopped.

aRsBdsH.png


The brass from 43.3Gr looked ok, the primer still have a radius to it, with a slight impression of the ejector hole on each brass.
cLEhyDV.png


This is my first time reloading for 6.5 Creedmoor so I don't know if it's the rifle or the load is too hot.
 
diegocn said:
I was working up the load for 6.5 Creedmoor.

The rifle is a Savage 10 action with a 22" barrel from Savage Axis. Head space is checked and the bolt will not close on the no-go gauge.

The load data is as follow:
Brass: Sako 6.5 Creedmoor
Primer: Dominion LR
Projectile: Hornady .264 140 Gr BTHP
Powder: 6.5 Staball
COAL: 2.822"

Hodgdon data called for 40.0~44.0 Gr of 6.5 Staball, with 2535~2806 fps out of a 24" barrel.

When I get to 42.5 Gr of charge I started noticing bolt lift becomes hard. At 43.3 Gr the bolt lift becomes quite stiff that there's definitely something not right about it. So that's where I stopped.

aRsBdsH.png


The brass from 43.3Gr looked ok, the primer still have a radius to it, with a slight impression of the ejector hole on each brass.
cLEhyDV.png


This is my first time reloading for 6.5 Creedmoor so I don't know if it's the rifle or the load is too hot.
Click to expand...
I just did some googling. Your results are typical. 4350 seems to generally get a bit more velocity. Some said the Stabol pressured up fast. I reload other cartridges, but if I reloaded 6.5 CM, I would heed your results and try 4350 if I wanted more velocity. Many loads on the internet are faster than reloading manuals because the pressure is higher.
 
Not familiar with that powder. I have some 6.5 experience.

Because of the long bearing surface of 140 gr 6.5 bullets, pressures can get out of hand quickly. Every rifle is different and it only take a small difference in the chamber/throat to make a rifle develop pressure more quickly. For this reason the results of others and the loading manual may not be of much help with a particular rifle.

Bolt lift is a clear indication of excess pressure.

I think I see shiny spots on the case head form the ejector hole. It takes a lot of pressure to extrude a case head into that little hole.

Back off or try another powder. My best results are with H4350 and N150.
 
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Yea your load is getting hot with heavy bolt lift regardless of what book max says. Always follow what your rifle says.

I get some great velocity from RL16, but it is unobtainium, and N555, that I'm currently using with 139 gr scenars. The scenars didn't like 4350. Mine didn't like staball either, but a 7mm-08 does.

The H4350 worked well also for the 130 gr Bergers I used up.
 
That's a bummer. I see 2 nodes in the data, first one is from 41.3-41.7 grain, the 3 shots ES is great and the velocity didn't change much. Probably some potential if I do a variable COAL test. But 2593 fps from 22" 6.5cm seems rather disappointing. Then there's another node at 42.9gr with good ES but the pressure is becoming a problem.

I do have some IMR4350 at hand that I can try.
 
I would get a jag of H4350 or even varget to do the load development as the powder price has fell to relatively reasonable price now.
 
From developing and "working up" loads in a number of cartridges here, I would say you have pretty classical signs that the combination of components, and your loading process (depth of bullet seating, etc.) are showing you pretty clear signs of high pressure - as per Ganderite above in Post #3, if that is brass flow into your extractor, that is way over "normal" pressure levels. Is the purpose of load "work up" to find what your rifle, your chamber will need - the manuals and other sources did not likely use your rifle for their testing - no reasonable basis to expect, always, to get same results. I am elderly "fudd" - I tend not to "trust" various computer simulations to say my load is okay or not - I want to "prove" to myself by firing - although I know several re-loaders my age, that use various computer programs to make load recipes and to make pressure predictions.

You can probably find article by John Barsness - he took a number of his loads - some that he had been using for years - to Western Powders lab and had them pressure tested on their tooling - discovered several of them well over established "norms" - and that in many cases, the "home done" signs of hard bolt lift, etc. were not reliable indicators of breech pressure - he concluded that muzzle velocity was, though - he never found that muzzle velocity increased, using the same powder, where breech pressure did not. With finely machined "custom" actions, he found he was not getting hard bolt handle lift - even though the load was significantly above "normal" pressure. That would put you into the "safety factor" of the action design - some of us would prefer not to go there. In one case, I think he was getting hard bolt lift, even though the load was well below standard pressure levels - presumably, that action was not machined as well as it could have been, or maybe he got much different results with a different batch of brass?

https://www.shootingtimes.com/editorial/reloading-myths-for-rifle-cartridges/371443

Portions of what he wrote in that article, can be found in articles that he did for "Handloader" magazine, and in some of his books.
 
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OP, IMR or H4350 works OK but has a very tight "OK zone" of only 2.0 grains between minimum and max loads.

This isn't just for IMR4350.

I tried it in my rifle, a cheapy Turqua that shoots what it likes well but has a crappy bedding system.

I've been playing with N550, because I have several pounds on hand and Superformance.

Superformance appears to be the best choice for both the Hornady 129 grain SST and 140 grain SST in as far as predictable consistent accuracy and velocity goes.

I realize you have to work with what you have as presently many powders are not available or priced out of reach. There are many of the more recent additions to the markets that I don't have in my stocks and don't intend to purchase because of the cost and frankly I have enough on hand for the rest of my shooting career.

I've tried slower powders, such as H4831ssc but velocities and accuracy aren't predictable and that's not a good thing.

I've also played with faster powders, such as Varget and RL15 with poor IMHO results.

This is a small case for the type of bullets you are using and like all small cases delivers some quite remarkable results.

Don't try to make the 6.5cm into something it isn't and wasn't designed to do and it will perform in an exemplary manner.

We've all tried to hot rod these types of cartridges, such as the 7.62x39 but in the end the results are lacklustre at best and hard on the firearm.
 
Ball powder is never my go to for accuracy.
I've always found it finicky compared to extruded. Meters nice and consistent, love it for blasting ammo in 223/308, but never get anywhere near the accuracy of extruded.
Some of it is better for velocity, but groups open up.
Keep working on the load, break the rifle in, my Savages start to shine after 600 rounds, at that point it's a different rifle and things get happy.
My best accuracy with my 6.5cm was actually with IMR 4064, FL sized on the left, shoulder bump middle, neck sized right. Same loads.
But don't neck size, thats really bad apparently.
20200816-181204.jpg
 
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Have you measured the distance to lands for that rifle? Bullet seating depth has a huge impact on pressure, and the COAL listed in the manuals is based on industry limits for feeding and magazine dimensions, which have nothing at all to do with pressure. You might find that you have some room to move that bullet out some more, which can lower pressures. Be careful though, jamming it right into the lands can have have the opposite effect, and might make things worse for you.
 
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