Could someone run me quickload data?

[Randy Bohannon]

Interesting - I was about to post a question regarding the possible uses of Quickload (and limitations) following what I thought was a rather surprising result with a couple of .223 loads. For a number of years I've been using 23.8 gr N133 behind either 52gr SMK or A-Max, COL 2.244". It gives me very good results, is not a compressed load but the primers are somewhat flattened after firing.

Just tried 25.5gr N140 behind 55gr V-Max, COL 2.244" per VV load data, and was surprised to find that the powder filled the case to the extent that it was probably 100% or even a little compressed, even after carefully shaking the stuff down. I was thus expecting to see signs of pressure, but no..... the primers had retained their shape, and the round turned out to be very accurate.

My question was thus going to be whether it would be worth me buying Quickload to get an indication of whether the case was overfilled and whether there might be pressure issues with some of the combinations that I have been using? I've yet to put the N140 round over the chrono but will do so this weekend and compare to the N133 rounds.

It's a SAKO 85, 1:12", 20" heavy barrel. Is Quickload worth having for occasional checks on loads which are well within the powder and projectile manufacturers' limits?

Apologies for the tardiness of my reply, I couldn't face typing it out on a phone.

You N133 load is a little over the minimum charge given by viht load data and you are in the right ball park velocityt wise given viht data is from a 25" barrel, guessing yours is a little shorter?

Given that the velocity is around 300-400 fps below the maximum obtainable I would suggest that your flattened primers are not a sign of high pressure. Flat primers can be caused by headspace using full length resized brass or simply the shape of the primer pocket. Cratering around the firing pin ( unless you have a Remington with a sloppy firing pin hole like mine) is a better sign as is ejector and extractor marks, indicating the pressure is high enough to make the brass flow past it's elastic limit.

This limit depends on the make of brass but is generally somewhere between 50-70 kpsi.

If you are owrried about the primer pop one out and measure it to see if it has become "top-hatted" or flowed into the ring around the primer pocket.

The reason I mention this is that when you are using a published minimum load and achieving the published velocity for that load, it is likely that you are also achieving the pressure the lab got when deriving the data.

The magnitude of this pressure isn't actually very important to you, believe it or not. I say this as your aim is to have long brass life, as far as pressure affects your load, together with accuracy, etc.

So if you are using soft, let's say Remington, brass your maximum working pressure is lower than when using Lapua brass. Even if the internal case capacity of these two brands were identical I would bet you anything the Lapua will digest loads without any pressure signs that would have you hammering the bolt of your rifle open with a bit of wood had you used Remington.

The point to take away then is that the absolute value, saying this load is Xkpsi, is not a very useful number for relaoders; does your brass last for enough firings at your chosen load or not; if no then you are running your components too hard, if yes then no worries unless you have oil in the barrel, carbon in the throat, etc.

QL therefore becomes a tool that you can calibrate to your components and rifle with a lot of shooting and experimentation and so therefore cannot not save you any experimentation by definition.

The issue with compression is that simply stated, there is no issue.

Compressing rifle powders is very unlikely to give problems, certainly not from a pressure point of view if the powder being compressed is being compressed because it is slow burning for the calibre/bullet combo.

They in fact tend to shoot better than loads with lots of room in the case due to more consistent ignition.

That N140 load seems very low pressure, did it leave the case sooty?

I suspect it will chrono out at 2800-2900, meaning even less pressure than the N133 load.

I have noticed that you haven't given case capacities as per:http://www.6mmbr.com/Quickload.html

Quick load can't give you an indication of compression without an accurate, measured, case capacity; even then I think it's not really very relevant.

Try a long (12" +) drop tube.

[severnsider]

Apologies for the tardiness of my reply, I couldn't face typing it out on a phone. You N133 load is a little over the minimum charge ………………………………………..Try a long (12" +) drop tube.

Thank you very much indeed for your observations and advice - very kind of you.

Yes, my barrel is 20" (rather than the 25" used for the Viht data) and the velocity seems OK. Interestingly, and on your suggestion, I have just looked at one of the flattened primers and it has "top-hatted" slightly (but no cratering around the firing pin depression). I use a variety of brass, and have never had any difficulty in extraction, but all primers with the N133 have exhibited flattening - which is why I was pleasantly surprised to see that the N140 showed no signs. Perhaps it is a slower round; I'll chrono some at the weekend and see what I get, but there was no sooting of the cases.

I'm now less concerned about the full case/slight compression; thanks for the link to the 6mmbr QL review. Very interesting.

Once again, thanks very much for taking the time to provide such a helpful response to my query.

[severnsider]

I suspect it will chrono out at 2800-2900, meaning even less pressure than the N133 load.

Came out at an average of 3000fps over five shots today; just about 100fps less than my 52gr A-Max/23.8gr N133 load. All very interesting - I shall save all the info into Strelok for future reference.