.20 practical 3rd OCW test

[gunner]

Hi folks , have been meaning to get out for ages now and do another test on the practical. I do have a pet load using N133 but was advised in a post ages ago by Mr Laurie Holland himself to try N140 in the .20s so here is a quick test at 100 yards , had a bit of mirage from moderator but it went ok . Pressure was staring to show on the primer edge of the 24.8s so don't really want to go any further ! Thats the beauty of quick load i plugged in the figures and before even firing a shot or loading it id worked out a 'window ' and loaded accordingly ... Its not mid summer yet either so have to be careful with loads developed in spring / winter- as everything gets warmer it shows in brass / trajectory /primers etc.

  All cartridges were loaded to the same 2245 cartridge overall length. I think my bullets are about 8-6 thou off the lands so it may be a very different load in your rifle. My barrel is a 9 twist Krieger so itl natrully be higher pressure in the same cut chamber but say a 11or 10 or even 12 twist . 25-1/2" long just for your info. Hopefully pikky will show . I haven't bothered measuring the group sises yet , as I'll probably confirm one or two of the groups then try them at 200 

Bullet was 39 Sierra B-Kingz naturally . Brass was shoulder bumped , neck sized in type S bushing die . Trimmed to length chamfered and annealed .

[srvet]

24.6 looks promising. Have you got a chronograph?

[gunner]

No mate I don't, honestly I've never needed one . Normally I'd get the load right then zero ,then confirm drop @400 yards in inches. But without dialling. Measure the drop in inches which then should equate to the same number of clicks on a 1/4 moa scope. Then confirm the impacts at 400 dialled. Besides QL does give a ballpark figure. But one day I may get one. I would then plug in that data to strelock pro and Normandy ballistic calculator and print out a chart. Now on my .20 I limit my shots to 400 . But on my 6br I'd do the same but confirm the drops out to over 700 then make sure it matches the drop chart at every 100 yard interval. Probably sounds a bit unorthodox but it's worked good for me . 

On the loads I think I'll try 24.4  24.5  & 24.6 now and see where it's at . I nearly bought a battery powered small portable fan so I could blow air across the top of the moderator as heat haze was a bit fuzzy. So may help. I will try and get out this week to confirm the loads etc . ATB 

[VarmLR]

I'd agree that 24.6 looks promising.  Mind you if it wasn't for the flier on 24.8, that looks much the same as the 24.4.  Might be worth repeating 24.4 to 24.8.  Without a chrony it's hard to draw too many conclusions but that bullet/powder combo seems to be quite tolerant across that range.

[baldie]

Put a Benchrest primer in it.

federals are good for marlins.....and thats about it.

[gunner]

Thanks for coments , dave i use federal 205 match ? Although im still to try some muroms kvb magnum things to try , but still need to get some from hps ! Which benchrest primers are the most commen ? Thanks 

[VarmLR]

You could try CCI, either magnum (450) or benchrest primers or Remington 7 1/2. Both good, both seem to be in plentiful supply.  I haven't heard too many negatives on the Federal 205GMs though....never tried them myself.  Muroms are ok although I think that the CCI and Remi's give higher velocities (at least in mine).  Murom KVB-M (not the KVB223 which are to be avoided imho) gave good low SD and ES but I didn't find them any better than the CCI's in mine...just a lot cheaper to buy.

[baldie]

As above really.

I use BR2's and BR4's predominantly, and the rem 7.5's when available. These are even harder than the CCI's.

I've always stuck to these, as you get used to seeing what they look like , pressure wise.

Feds are excellent primers, but soft, so will show pressure signs quicker and frighten you, when the load is probably not hot.

They are a favourite with Marlin shooters as you can drop the Hammer spring weight right down, to give a light pull, but still set the soft primers off reliably.