Is this a reasonable or idiotic assumption for working up safe loads in 7x65R?

[1886nut]

So, I've recently come into possession of a post WW2 made 7x65R falling block, and of course I bought a few boxes of factory ammo as deer season starts soon down here. I've also bought a good supply of brass, already have 7mm bullets, and the bore slugs properly for 0.284. Theres plenty of load data out there for the 7X65R with various powders, Norma 204, IMR 4831 etc.

Heres where your opportunity to let me have it comes in. Like a lot of members here I have an ample supply of IMR 4895 powder for the Cal. 30 milsurps. I'd like to use some up in loads for this cartridge. Norma 204 has loads for both 30-06 and 7x65R. Can I assume the same charge weight differential will allow me to calculate a safe load of 4895 in the 7X65R, taking into account case capacity (including final bullet seating depth)?

OK...roast me.

[Milky Duck]

assume NOTHING..... find case with nearest capacity you can...and start low,working up a little bit at a time,no need to load up 5 at each level,just a single round at each till get pressure or are happy you high enough.
BE CAREFUL.....a rifle self distructing in your arms,next to your face IS NOT FUN....
again,please be careful.
Im GUESSING here that your imr4895 is a similar powder to AR2206........ great in .223 or .308 but not so flash in the 270 as not a good volume .....
be careful.....find some hard data on paper......be careful.

[pworley1]

The 7x65r is basically a rimmed 280 remington. You should be able to use 280 starting loads and be ok.

[1886nut]

pworley - They are close but I dont see any 4895 loads for the 280 Rem. on Hogdons data center. Maybe 270 Winchester bottom starting loads with similar bullet weights are a good start?

MD - Understood....can you get detonation instead of combustion if the powder charge lies too low relative to the primer pocket?

[GregLaROCHE]

There are powder burn rate equivalent charts on the internet. I use them to compare European powders available here to US load data. They are not exact, but give you a good place to start.

[P Flados]

pworley - They are close but I dont see any 4895 loads for the 280 Rem. on Hogdons data center.

From Quickload, the 7 x 56R has a slightly higher case capacity and a slightly lower allowed chamber pressure as compared to the 280 Rem. These two tend to offset each other such that starting low based on 280 rem data should be a good starting point.

I had no trouble finding H4895 loads for the 280 Rem in the Hodgdon on line load data. The differences between the two cartridges is bigger than the difference between IMR 4895 and H4895.

[Milky Duck]

not so much problem with ignition...but its always been "one of them things" pretty much accepted as gospil...the fuller the case the better . from memory I was getting 2-3" groups vs my normal hovers around the inch mark.

[Gamsek]

7x65R is rimed (R) version of 7x64, I have both. Using just different shellholder you can use same reloading dies to reload both-beside rim identical on outside.
With 160grs bullets and same powder, following the reloading data, you get approximately 100fps less velocity with 7x65R.

So if you can find data for 7x64, with same powder you can easily make good load for 7x65R. Difference between max load for 160grs Nosler Accubond with Vihtavuori N150 and N550 is 2 -3grs. Check theirs web site with reloading data to get a feeling. I load both calibers with N550, 7x65R has lower pressure - break open combination guns.

[1886nut]

The .270 Winchester seems like its pretty close, slightly shorter shoulder. So would it be foolish to put Hogdons starting loads of 4895 for the .270 into the 7x65R (both with 150gr boolits) and work up 2-3% from there? I'm just trying to work up a short range (less than 200 yards) hunting load for white tail bucks and use up a powder that I have aplenty.

[popper]

H4895 can be safely downloaded. IMR4895 not. Look for youth loads of H version.

[1886nut]

What makes a powder unsafe to download? Detonation from laying too low relative to the primer pocket?

[Hick]

[can you get detonation instead of combustion if the powder charge lies too low relative to the primer pocket?[/QUOTE]

If the powder charge is around 50-60% of a full case, and you lie the bullet on its side, you can create a situation where the primer hole is uncovered and the powder is lying lengthwise in the case all the way to the base of the bullet. This will dramatically increase the burn rate, simply because the flame from the primer hits so much more powder all at once. (that is, the individual grains of powder are not burning any faster than normal-- but many more of them are burning all at once)

[BLAHUT]

Compair burn rates if similar you can use if not do not touch look for trusted load info use that if you can find either way start with reduced loads

[uscra112]

I've heard this one ^^^ for as long as I've been a reloader, but I've yet to see controlled experimental data to back it up. One of many urban legends that grew up around the SEE phenomenon, until that was adequately explained with lab data.

Modern Schuetzen shooters use smokeless loads that are very often less than 50% load density, with remarkable accuracy.

BTW smokeless powder cannot detonate. The chemistry is all wrong.