.243 Winchester and Quickload

[Heman]

For all my cartridges quickload is ussually spot on or fairly close to actual measured velocities, however with my .243 it is a different story and I'm needing some help here.

I'm loading 105gr Nosler CC's to an OAL 2.936 with 44.5gr of IMR-4350 Worlf LR primers and Winchester brass out of a 26" 1:8 twist Hart barrel. I've worked the load up and while the primers flatten I'm not getting any pressure signs as far as extractor marks on the brass, etc. Today I went out to chrono the load and I got around 3005fps on a clear day with Temp at 45 degrees. Quickload is showing 3056 fps. However with the other charges I used today 43.5, and 44gr they all should have been at 3000fps or faster and they weren't. low 2900's mid 2900's respectively. THis caused me to wonder what is up. I noticed that the weighting factor for the .243 is 0.65 but when I input my case dimensions it calculates a factor of 0.49, I changed this and it made the velocity higher so I'm at a loss as to what is going on. I was going to adjust the powder numbers for my lot of IMR-4350 but in my .30-06 it is dead on, so I'm kinda at a loss here. Load works and I'm gonna go with it just kinda curious as to why quickload is off so much.

Thanks in advance.

 

[Tripwire]

Re: .243 Winchester and Quickload

Is your load accurate, and can you accurately confirm/deny a calculated dope via rounds down range?

Big damn deal what QL says, it's a rough draft at best.

Go fucking shoot your dope in.......

 

[Heman]

Re: .243 Winchester and Quickload

Sir that is the problem I don't have access to a range to shoot past 100 yds unless I'm shooting a match and with only 2 sighters for NRA mid range matches I would like to have an idea what my velocity is so I know what my comeups should be aproximately. Plus Im mentioning this becasue I find it odd that QL is on for my other cartridges but so way off for this one.

 

[Tripwire]

Re: .243 Winchester and Quickload

If one was serious about shooting a "match" then it behooves one to have a place to practice/prepare for said "match".

Not trying to be a hardass but NOTHING replaces rounds down range.

Anything else is just a guess....

 

[Heman]

Re: .243 Winchester and Quickload

Well I've shot competively for the past 3 seasons NRA across the course, mid-range and long range. Working on my high-master card for mid and long range. So sir I do send rounds down range. My practice comes from the matches at the various ranges (Atterbury, Ft. Knox, Perry, etc.) and shooting small bore. I was just looking for some help and advice on the Quickload issue. Sorry I bothered everyone on this topic I shall drop it.

 

[Clark]

Re: .243 Winchester and Quickload

I have never had an IMR4350 or H4350 load that was as fast as Quickload predicted.

I only have a 1 pound jug of IMR4350 and a 6 pound jug of H4350 that I have shot over a chronograph.

In a 243 sized case, QL is going to over estimate the pressure and velocity of my H4350 jug by 2 gr.

Where my IMR4895, Re22, Re17, and Varget QL predictions are right on the money.

Off the lands is ~ 2kpsi start pressure to get the right answers.
Jammed into the lands with tight neck tension is ~5kpsi starting pressure to get the right answers.

I don't know if it my 4350 powder are strange lots or the QL library on those powders is not right.

In 243 with large Boxer primer, if the 4350 powder charge entered into QL is normalized [Diddled down ~2gr, for those of you in Rio Linda] so that the velocity prediction matches the chronograph, then the threshold of lose primer pockets will be ~ 74kpsi. Once that all matches and I know where the threshold is, then I back off a safety margin for my own process control variables and load quantities of ammo at 67kpsi.

 

[Heman]

Re: .243 Winchester and Quickload

Thank you for the response. If I enter 43.5gr then it matches what I've noticed with 44.5gr.