Home Forums Reloading Big Game Rifles Chrono'ed some 7mm-08 120 NBT loads

The load and velocity comes from the Nosler manual (#6).

What is CHE?

P

I don't have Nosler's #6, but load data from their website shows a max velocity of 3090 with H4895.........that's a long way from 3277. The other 4 powders they list there are lower than that. And their data is from a 26" barrel.

CHE = case head expansion; "experts" here say by the time you get measurable CHE, you are waaaaaaay high on pressuer.

MM

Nosler #6 data for the 120gr ballistic tip lists as max 52gr big game at 3262fps, 50gr at 3190fps.

Nosler doesn't post all of their loads online.

How do I measure CHE?


P

Accuracy in my -08 is best at 50.0 grains of BG but even at 50 gr. I am a little hot. My 22" barrel is chronographing just a hair over 3100 fps. so I'll go no higher. As a matter of fact, I am going to search out a slightly milder load that will give me accuracy as good as the above load and be happy. I bought a 7mm-08 in the first place to get away from the recoil of the faster 7s. I've tried RL 15; will try Varget, H4350, H4895, and maybe others. Just my thoughts....

In my experience the velocities quoted for the 7mm/08 in the Nosler manual can be as much as 200fps-250fps above what is achievable in the real world. I've had a 7mm/08 for 17 years and chronographed many hundreds of loads and none come close to the velocities published in some manuals

My 700VLS 22/250 produces velocity 200fps less than Noslers pulished data with Varget/50gn bullets despite my rifle having a barrel two inches longer than Nosler's test barrel.....Go figure.

I'm thinking you meant that the real world is below what Nosler publishes???????????

MM

CHE is measured with either a blade or a pin mic by measuring the diameter of the case just forward of the groove.

You need to use virgin cases & measure before & after firing a test round.

Measurements will be in tenths of a thousandth & as I said before the "experts" here have decreed that any consistently measurable increase in CHE means a load is too hot..........IMO, consistently measurable is .0002-.0003"

You can do a search here for CHE or case head expansion.......several extensive & heated threads over the last 3-4 years.

MM

Your right,thats what I mean.

+1 on that. I haven't worked too much with my Sako yet but 41 gr of IMR 3031 (the powder I had on hand) and the 120 gr TTSX is grouping nicely with mild recoil. Haven't chrono'd yet but should be 2900-2950 fps as a guess--Hodgdon lists a hair under 3000 fps with that load. I wonder how the 50+ gr loads of other powders at 3200 fps these guys are using compare in the recoil department?

sambo3006......recoil is not bad, just a sharp crack....my load is 51g Big Game and 120ttsx @ 3130@ muzzle. Deadnutsaccurate...

In my Cooper the 50.0 load of BG and the 120 gr. NBT shows a little primer flattening and an ejector shiney spot. I am first going to try partially re-sizing to make sure it's not headspace; if not, I'll reduce the load and/or try different powders. I haven't worked with the TTSXs yet, but they are on the shelf.