Working up a load ... getting conflicting data?

[ronedog]

I am working up a load for an older gun I've had. I had to buy a different powder (IMR 4350). I thought I'd search the web to learn a bit about load recipes that have worked for other people and back off from there a bit to start testing the powder charges.

But, I've gotten a bit confused, there are some manuals that say not to go above what others have done and seem to be fine with...but the amounts above seem rather high, I've listed some of them below.

I've read a number of other threads of people who say around 56.5gr of IMR 4350 with a 165 bullet worked good, but I've got 185 berger VLD's.

A few years ago, I pressure tested the rifle, and my notes from a few years ago said with H4350 powder, at 59gr started to show signs of sticky bolt and imprints on the case...but that was a different powder than what I have now....logic says to pressure test with the new IMR 4350, but others have suggested that powder is similar enough to H4350...i dunno?

I was thinking of doing an OCW starting with the following: 55.5, 56, 56.5, 57, 57.5

But, when I poured in 55.5gr of IMR 4350 with an berger 185 VLD, seated .010 off the lands, the bullet I could hear began pushing against the powder...is this ok? It didn't crush the powder, and I didn't have to press it in very much, I just noticed it. I normally have been loading 300WSM and haven't noticed that before.

The bigger concern came when I opened my Richard Lee reloading manual. He has the max load for 180gr jacket bullet at 52gr. And Berger's website has it at 54.4 for a 185VLD hunting IMR 4350. Yet, Hodgdon's websit has the max load at 56.5 for a 180 bullet IMR 4350.

Thoughts? Should I continue loading for the OCW listed above, or go lower and start from there? Is IMR 4350 that much different from H4350, where the 59 gr max pressure test from a few years back should be thrown out?

Thanks for any input!

My gun is:
Gun: Ruger M77 Mark II 30-06 Springfield
Powder: IMR 4350
Bullet: Berger 185 VLD Hunting
Primer: CCI #200
Brass: Winchester (fireformed, FL sized, shoulders bumped .002 thousands)


I found this recipe from someone else:

Berger Says this about the min/max starting loads:
https://bergerbullets.com/pdf/30-06-Springfield.pdf
min: 49gr
max: 54.4gr

The Modern Reloading Second Edition by Richard Lee has this for min/max starting loads for a 30-06, 180gr bullet, IMR 4350
min: 49gr
max: 52gr

Hodgon says this:
http://www.hodgdonreloading.com/data/rifle
min: 53gr
max: 56.5gr

 

[dok7mm]

Different manuals use different bullets with different bearing surfaces, so you can have different pressures. Equal weight does not mean they have equal bearing surfaces, so you have to start low and work-up. If you have a good chronograph, you can see the difference between bullets with different pressures/speeds.

 

[cajun]

I always try and use the bullet makers data if possible. I will reference the powder company data as well. IMR 4350 and H 4350 are not the same powder. Use bergers data and work up.

 

[dok7mm]

Also, check test barrel length and COAL, used in each source.

 

[ronedog]

Ok, thanks guys...I'll start with Bergers advice and work up from there. Thanks

 

[Bob Wright]

Do a 10 shot ladder of each, starting loads should be your baseline on the manual if you have no experience with that powder primer combo. Take it in .5 gr increments up to 1 to 2 grains over max listed. Find your pressure point where you have primer flattening, extractor marks, heavy bolt. That is your absolute max. Do it over a chronograph.
Mark each shot on the target. It should be at 300 yards. I use a Go Pro camera set to 2 minute intervals at the base of the target to record shot string. You'll find a node in there that flattens out for 2 or 3 rounds. That's where you do a seating test within the highest node. Once your seating test determines the best depth, then
check the powder charge within that node from the low to high. You'll hopefully find the higher part of the node will be repeatable and group well. I choose the higher velocity powder for seating and working in that node. Hopefully you get good ES and groups.

 

[ronedog]

Thanks Bob!

 

[Mikecr]

My IMR4350 is slower than H4350. I think your plan to shift over is a good one.

 

[Tiny Tim]

Agree with others. Bullet is a huge factor in loads due to bearing surface, bullet hardness, bullet composition, and other factors. Barrel length should not affect pressure but will influence velocity. As for stating that the two are close in burn rate is true, but so is lot to lot variation. Any time you change powder, whether it be lot number or type, you should back off and work up again.

 

[Mike Matteson]

Barrel lengths do effect pressures, which effect velocity. Using slower burning powder the pressure is gain over a long period of time going down the barrel. Still it's higher pressure the higher velocity. That why using slow burning powder don't work well in short barrel lengths. You don't gain the pressure to push the bullet down the barrel. The pressure isn't as great at the start, but builds over the length of the barrel. That why pistol powders are faster, because of short barrel lengths or wheel guns.

 

[Mikecr]

Barrel length in itself does not affect pressure peak (which is within an inch or so of bullet travel). But muzzle pressures rise if your powder isn't yet burned before reaching it, and because the pressure curve has not fallen as much with a shorter barrel.
Velocity comes with TIME of X-pressure push. That is, through acceleration, which is time dependent.
If you had a 55Kpsi pressure peak with only 3" of barrel beyond it, then the bullet will only accelerate for that 3" and reach maybe ~1/3 of the velocity it could reach with 30" of push.
With the 30" barrel length, the 'pressure' seen by 3" would be the same, and the pressure by muzzle would be way less (~8Kpsi).

 

[Tiny Tim]

Barrel lengths do effect pressures, which effect velocity. Using slower burning powder the pressure is gain over a long period of time going down the barrel. Still it's higher pressure the higher velocity. That why using slow burning powder don't work well in short barrel lengths. You don't gain the pressure to push the bullet down the barrel. The pressure isn't as great at the start, but builds over the length of the barrel. That why pistol powders are faster, because of short barrel lengths or wheel guns.

Pistols also run faster powders because the case and bite are nearly the same diameter. This is partially why some large bore rifle cartridges such as 444 Marlin and 35 Whelen run relatively fast powders compared to a cartridge with the same basic parent cartridge but with a smaller bore. The overbore cartridges will benefit more from slower burning powders and they require more barrel length to be more effective.

 

[Vol1975]

Manuals, web sites from established places & maybe a call into companies for load data are a good start but always start well low of established known data. personally I don't get load data from web pages and load up in shoot in a gun. I might cross reference it and make notes on what people say shoot good in certain calibers and bullets.
also, If a manual says start at 60 grains with x bullet then why not load a couple low loads at 59 just to have a check and foul the barrel with x powder. Every powder, barrel, etc is different.
also ive seen some guys never check loads with a chrongraph. personal this to me is dangerous For a variety of reason.
just my 2 cents.

 

[Mike Matteson]

I have generally found that reloading manuals are on the low side of what the cartridge or rifle will do. So people seen to want to play around and it appears it doesn't brother them that primers are coming out of it's pocket when the round it fired. There only been once i used the manufacture load chart, and when straight to he top powder load using their bullet. I blew a primer out of the case. I only fired one round and that was it for the bullet. I still have the box of bullets and the reloading data in the box. That was in about 1975. I started hand loading in 1962 at age 14 with a 300 H & H Mag in Rem. 721. I did a couple of other times with temperature with IMR 4350 powder. Gave away about 16 pounds of IMR 4350 and 4831. Never use that powder again and that was in about year 2000. I do load beyond what the manual shows, but blow primers out the their pocket no. Chronographs is a must, and without it you know nothing.