I just loaded up some 7mm-08 shells for a new gun and noticed there was an unusual amount of empty space in the cartridge. Since I am fairly new to the relaoding game, I was wondering how this affects performance/safety.

140 gr Rem PP
42 gr BL-C(2)
New Win Brass
CCI 200 Primer

Thanks

I just loaded up some 7mm-08 shells for a new gun and noticed there was an unusual amount of empty space in the cartridge. Since I am fairly new to the relaoding game, I was wondering how this affects performance/safety.

140 gr Rem PP
42 gr BL-C(2)
New Win Brass
CCI 200 Primer

Thanks

Even with that BL-C(2) laying on the bottom two-thirds of the horizontal cartridge, when that CCI 200 gets touched off, that powder will ignite just fine.

There's nothing wrong with having some space in the case as long as you're following good load data. Many on this board, myself included, prefer powders that give higher load densities (less space or no space left in case). However, I've got some loads in my 270 with varmint bullets that have plenty of empty space in the case and are still very accurate.

amndouglas

I load 9gns of unique in my 38-55 with cast bullets and that leaves all kinds of space. Original load as stated 55gns of black. Don't worry, if it bothers you go to a slower burning powder and fill the gap. Back when the 7mm/08 was a wildcat most of the guys using them were benchresters and I belonged to that group, most were using IMR4320 and 4350 with 140gn match bullets and a few were using WW760 with the 168 Sierra Match Bullets.

I wrestled with this issue several years back when I was a reloading newbie. My view was more related to safety than performance as I didn't want to risk blowing up a gun and suffering the consequences. I always develop loads with the intention of using a slightly compressed load. The reason being - I can never overload the case with powder and blow up the gun unless I use the wrong powder which is a lot less likely than using too much powder. I gave up on handloading my pistols for a number of reasons and only handload center fire rifle cartridges. I have been successful at developing highly accurate loads that use a slightly compressed charge for all my center fire rifle cartridges and I really enjoy tweaking them for a high level of performance. Factory cartridges that I have pulled bullets from always have a compressed load and my realization was there must be something to it or the experts wouldn't do it.

Hey - it works for me.

According to my Hodgdon #27 reloading manual, you're 1/2 grain below their maximum listed load.

Depending on the condition of your firearm, you should be OK.

This load seems to be ok, especially with blc-2, it is a pretty slow burn powder. Keep in mind however, that the case capacity should not get below about 70% due to possible flash over the entire load when the load gets down anywhere near half density.

There are examples of this on the saami website and also on several of the powder sites as well where the primer was nearly level with the top of the powder and instead of a steady burn rate the entire case flashed at once, blowing the gun and case out.

That can not happen with smokeless powder... Smokeless powder burns, and produces gas. Blackpowder explodes.

...an unusual amount of empty space in the cartridge. Since I am fairly new to the relaoding game, I was wondering how this affects performance/safety.I presume you don't mean "unusual" in the sense that other times you've loaded that load the case has been more full. Under those circumstances, you might have loaded this one in error.

Presuming you meant there just seemed to be a "lot" of empty space, the others are right - no danger.

Performance is different, however. Accuracy requires repeatability, including the way the primer ignites the powder. The reason many (most/all/?) of the most accurate loads are from cases that are 90%+ full is that it enhances this repeatability.

If all of the powder is packed up tight against the primer when it ignites one time, and the next time it ignites the top of the surface of the powder lying along the length of the bottom of the case, then you have poor repeatability. In the first case it ignited one amount of powder initially, and in the second case it ignited a larger amount initially. The eventual amount of gas created by the powder won't change - proportional to the amount of powder - but the peak will occur earlier in the second case. You avoid that by having a small amount of powder exposed (90%+ full, packed against the primer) each time and thus enhance repeatbaility.

In general. As have others, I have some loads that shoot fine with low densities.

Jaywalker

I try to avoid using powders that leave lots of empty space in a cartridge. That being said, if I'm loading a cartridge to only 20% of it capacity, I'll use dacron to keep the powder against the primer.

An example of this is, I load 16 grains on Unique in a .45-70 under a 300gr JHP. To fill the void and keep the powder in place, I cut a piece of dacron about 1 inch square and roll it up like a cigarette butt and slide it in using the allen wrench for the die lock-rings.

I would stay away from "cream of wheat" or other more "compressible" fillers as there is a lot of talk that this can cause micro-grooves in the chamber. There is a lot of debate on this subject as many have shot thousands of rounds with no problems and other report differently. My conclusion is it's more of a problem that results from compressible filler and/or double charges (which don't overflow a cartridge like a full charge would) so it's not as noticible of a mistake.

I just loaded up some 7mm-08 shells for a new gun and noticed there was an unusual amount of empty space in the cartridge. Since I am fairly new to the relaoding game, I was wondering how this affects performance/safety.

140 gr Rem PP
42 gr BL-C(2)
New Win Brass
CCI 200 Primer

Thanks
Buck - I don't load 7-08 but a good rule of thumb is the powder should take up about 90% of case capacity in rifle rounds -you may need another powder ( the IMR extruded powders should work well - 4064,etc) check the manual for recommended loads

What I meant was that in comparison to the other rounds I load for (30-06, 30-30 & 8mm) this particular load has more empty space. I am going to the range tomorrow and will see how accurate they are compared to Fed. Premium 140 gr.

Thanks

Bucksnort

I reload for 7mm-08 (Rem 700 Mtn LSS) and have tried several different powders. Just to confirm what others here have mentioned, my most accurate loads seem to come when I've used 90% or more of the case capacity.

One of my more accurate loads is Speer 145 Grn SP (Hot Core) on top of a max load of 48Grn of IMR 4350. These loads are just slightly compressed and shoot between 1/2" - 3/4" groups at 100 Yds.

Another great powder for 7mm-08 is Varget. With this powder I get sub MOA groups with both 140Grn Sierra Game Kings and 140 Grn Nosler Accubonds.

Good Luck!

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