Thoughts and info on using IMR-4227 with light boolits (120 - 140gr) in .308

[supersniper]

I have a quantity of IMR-4227 to use and would like to see how it works with light boolits in the .308.

Anyone have any thoughts or experience with such a combination?


Thanks in advance.

[beltfed]

Why, Not?
4227 is very versatile with CB loads in 308s and '06's
I just copied some info off another thread here, suggesting
loads for .308 of 15-17 gr 4227 with 170 to 190 grain bullets.
Something like that should work with the 120-140 gr bullets, too.
Maybe a bit less or a little bit more for the lighter bullets?
beltfed/arnie

[bluejay75]

Get it into the lands. Get a good crimp. Most pistol powders work. My go to load at the moment is AA9. I wouldn’t dare shoot it without a crimp or into freebore though.

[Texas by God]

From the old IMR Handloaders Guide;
30-30 Win 150 gr jacketed bullet/ 20grs of IMR 4227 for 1905 fps
.308 Win 150 gr jacketed bullet/ 26grs of IMR 4227 for 2260 fps
Either load would be safe with lighter bullets; I would use the 30-30 level load for cast bullets.

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[John McCorkle]

Get it into the lands. Get a good crimp. Most pistol powders work. My go to load at the moment is AA9. I wouldn’t dare shoot it without a crimp or into freebore though.Ok good call out that I'm interested in here Jay

Seating bullet into the lands vs freebore with fast burning powder. I feel I would be concerned about bullet set back more than increase in coal under recoil...but I feel I'm missing something here

Could you expound?

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[supersniper]

Finally got to the range today and results at 50 yards showed that the 311359 boolit fit to the throat of .310 faired the best over the others at .308, .309 and .311. Throat was measured at .310. Velocity was right about 1900 fps with 19.0 grains of some old (tin can) IMR-4227 and filler. Next outing will attempt to dial in a more accurate loading with adjusting the powder charge. (311359 PC COWW quenched after coating) (Rifle is a custom built Remington 700 in 308 Win. with an 18" barrel)

[charlie b]

http://www.gmdr.com/lever/lowveldata.htm

I use the .30-30 load data for my .308 and it comes pretty close in velocity. Have not used 4227, just Blue Dot and 700X.

I would shoot more of these but they just don't do well at 200 or 300 yd, which is where I do a lot of my 'plinking'.

[MostlyLeverGuns]

Long ago I used 12 grs 4227 under the 311407 in the 30-30. More recently I've used 18 grs under the 145 gr FMJ military in the 308 and 300 Savage with excellent accuracy, very pleasant to shoot. I've also used 18 grs 4227 under Matt's Bulets 185gr .310 bullet with excellent accuracy out to 200 yards.

[supersniper]

Found an accurate load with the 308 using the 311359. Will now try to see if they can be pushed faster before running into the RPM threshold and if my experience with "accuracy nodes" using jacketed bullets holds as well with cast boolits.

[supersniper]

Well I concur with Larry Gibson's RPM threshold data having experienced it for myself during this testing. 10 twist barrel shoots well at 1800 fps with 122gr boolit and accuracy goes radically downhill when 1900+ fps is reached. Next step on this journey is heat treating this alloy to see what it will allow.

[supersniper]

UPDATE: 308 Win - 10 twist - 18" bbl - 311359 COWW powder coated heat treated (450 deg / 1 hour) boolit - velocity raised to 2400 fps with ok accuracy - just above that the RPM threshold kicked in and the accuracy really went south. Happy that HT has allowed for an increase in velocity with accuracy. Prior tests with .310 sizer left some lead ring shavings. This test, used .309 sizer with what appears to be more shaving than before. Next test with .308 sizer in attempt to reduce shaving.

Suggestions?

[popper]

SS IMHO you are going the wrong way. sharp front drive band is the problem. Hits the throat and gets clipped, then the rest of the bullet gets swaged down to proper size. IMHO chambers have a sharp edge at the case mouth that catches the 'ring', often attached to the mouth on ejection. it takes time for alloy to flow, sharp edge gets no time. Other problem is there is space between the mouth and chamber, alloy expands, then swages to bore, cutting a ring into the small space. again, usually attached on the mouth upon extraction.

[supersniper]

Popper, suggestions for a reamer or something to break that edge without lengthening the throat? Criterion SS match barrel that shoots J-words very well but would prefer not to change the current dimensions.

[supersniper]

UPDATE - Found that the dacron filler was giving me the issue with build-up just in front of the case mouth. All loads fired since have left no residue. Also, I switched to the 314299 210gr boolit and it is shooting right around 1 MOA at 100 yds using some old IMR-4227 (no filler) running 1820 fps and just over 1900 fps. Next step in this process is taking it out to 300 yds and beyond when time permits. I will also revisit the lighter boolit again only without the filler. Soon to be testing the NOE 311414 152 gr boolit in both the 308 and 30-06. Thanks to all who contributed to this post.