170gr 30-30 boolit at ~1700 fps - do I need a gas check with commercial bullets?

[gregw72]

I have gotten a ton of great info from Castboolits, but one topic that still is murky to me is gas checks. Lots of posts on them, but there seems to be two camps on whether you need them or not. I do not cast my own boolits, due to lack of time. I am trying to determine if I can launch a commercially available 170ish grain bullet at ~1700 fps (for rams in silhouette) without a gas check. Penn says their bullets can run up to 2000 fps without, and other companies say you need a gas check for lower velocities. What is the answer? I will be using a Marlin 336 with microgroove rifling. I would especially appreciate responses from those that are buying commercial bullets and are achieving this velocity or better. If I have to press on a gas cap, then I might as well just buy Speer JFP. Thanks!

[ShooterAZ]

I'd advise you to try them first, you will likely be fine. My own personal rule of thumb though is anything 1600fps and above gets a gas check. I assume that they are a gas check design? If so, you will likely achieve better accuracy with the checks applied. That's been my experience anyway.

[Larry Gibson]

I am trying to determine if I can launch a commercially available 170ish grain bullet at ~1700 fps (for rams in silhouette) without a gas check.

You can certainly "launch" them at 1700 fps. Whether the accuracy/precision will be there remains to be determined. Like ShooterAZ, I prefer a GC'd cast bullet above 1600 fps. I've also not had any decent (or at least what I consider to be "decent") at sonic speeds with GC'd bullets sans the GC.

[gregw72]

Thanks for the responses. Yes, I need this to be accurate... approximately 2 MOA. I've only shot cast in pistols and 44 Mag, where GC's were not needed due to low velocity (and the accuracy has been great, especially in 38 spl and 45 ACP). 30-30 is a whole nuther beast.

[popper]

2 problems. Commercial 'blue' lube is terrible. 2- it's a marlin that normally takes the larger harder cast OK so you need 311 - NOT 310. I'd go with the GC design first. It can be done PB but there is a learning curve.Try H4895 first for powder - it always works. LeverE is better but I save it for FTX jax bullets. GC go on easy with a Lee pushthru sizer die. For cast you need to get a neck expander die also. If it's a NIB rifle, I'd shoot the jax anyway for a while to break in the bore.

[FredBuddy]

Shoot j-words.

I have 2 Marlins, one a microgrove, and
of the 7 30-30's I have these 2 have been
the most fussy cast boolit shooters
I have worked with.

That's not to say it can't be done, but
as Popper says, there's a learning curve.

I've been trying to master the art of
the 30-30 for pert near 3 years, and still
going.

[gregw72]

Thanks Popper and FredBuddy. I was planning to use H4895 as that is my go to power for 30-30 (and every other rifle I have). You confirmed what everyone says: that I need .311 for my microgroove barrel. Wonder what makes the 30-30 have such a learning curve with cast and 38 spl and 45 acp were so dang easy. Velocity? Pressure? Powder burn rate?

[barrabruce]

Thanks Popper and FredBuddy. I was planning to use H4895 as that is my go to power for 30-30 (and every other rifle I have). You confirmed what everyone says: that I need .311 for my microgroove barrel. Wonder what makes the 30-30 have such a learning curve with cast and 38 spl and 45 acp were so dang easy. Velocity? Pressure? Powder burn rate?
Probably not expected to have any real accuracy past 50 yards.
But 30-30 3 or 4 times the distance at least even with dicky sights.

[atr]

do not overlook Win 748 powder in the 30-30. it works very well with cast.
atr

[popper]

29gr 4895, 311 cast and GC should be no problem. Expand the neck for 1-2 thous. neck tension and shoot away. Leverguns are not exactly target guns anyway but MOA @ 100 is not that hard. Marlin triggers aren't the best, 2 piece stock doesn't help much either. You can boil off factory (hard blue lube) in a pan of water, then use a good lube. Factory cast is usually hardball alloy which is fine. I cast mine but lasercast, MBC & some others are decent bullets I've tried. Might try 2 coats tumble lubed with BLL if you're not pushing past 2k fps.

[P Flados]

I am less convinced in the need for checks than some folks.

Missouri Bullets has a couple of offerings in coated 0.311 or so bullets in the desired weight range. For shooting steel, the second one might be worth trying.

.311 Diameter
165 Grain RNFP
Brinell 18
For Marlin Lever Guns
Hi-Tek 2-Extreme Coating

.312 Diameter
167 Grain FP - Grooveless
Brinell 20
For Mosin-Nagant
Hi-Tek 2-Extreme Coating

[gwpercle]

With the Marlin Microgroove a boolit with a gas check will make finding an accurate load easier.

For plain base boolits be prepared to do a good deal of testing .

My rule of thumb is I've never had a boolit shoot worse when a GC was attached...things always got better . Size .311 and be ready to try .310 and .312 and use a good soft lube .
Fit of the boolit to throat and bore is a lot more important than a super hard boolit .
No one magic answer to the Marlin Microgroove situation ...keep on experimenting untill things come together .
Gary

[gumbo333]

gwpercle, I'm sure that may be true, but if you are buying boolits, not casting, buying PC'd or Hi Tek may be easier. I've used both Missouri Hi Tek and Penn PC'd, like them both but I doubt I've ever gotten to 1700 fps. ( Penn PC was in .459, 45/70). Surely someone on here has. I've also shot Beartooth gas checked, 170+ gr (.310) in a 30/30 using LVR to maybe close to 2000 fps. They were excellent, as good as Speer 170 gr FP jacketed, maybe the most accurate 30/30 bullet I've found fooling around with 30/30's.

[lar45]

Hunters Supply has a .311 165 plain base bullet for $.16 ea.
https://hunters-supply.com/311-cal-165-p-190.html
They use my Commercial Grade 160 Green lube which can handle velocities well over 1700fps. I have many boxes of their boolits from .358 to .512, but no .311 sorry. I have not had any problems with leading with their bullets, but I have not tried the .311 165gn bullet in anything. If you do get a box and try them, I'd be interested in hearing the results.
I have pushed a plain based 160gn pistol boolit past 2000fps in my 35 Whelen while testing lubes without leading, so it can be done.
Let us know how it turns out.

[gumbo333]

I forgot, the purchased cast and lubed boolets I use I've tumbled in BLL just for good measure, gas checked or not. I think I've read on this site that guys have shot boolits to fairly high velocity's with just the BLL and no lube.

[redhawk0]

I shoot 170 GC seated and sized first 0.309" Then a double coat of Powder Coat. I don't resize again. Then seat and shoot W748 at 2000fps with good results. BUT....I'm shooting from a Win94 Ballard rifling....the Marlin MicroGroove is a different animal.

It might be worth removing the Blue lube...and try a bit of powder coat with your boolits.

redhawk

[lar45]

I just shot some 375 Supermag with the Hunters Supply 260, with and without a gascheck.
Adding a gascheck made a huge difference here.
http://www.lsstuff.com/pics/375sm/375smtarget-01.jpg
http://www.lsstuff.com/pics/375sm/375sm-01.jpg

You'll probably have to just buy some and try them to see how they'll work.

[gregw72]

Thanks for the lead on Hunters Supply.

I have tried the Missouri Bullets with the HyTek coating before in my 44 Mag Marlin 1894 and they leaded as bad as the non HyTek bullets. Was only shooting the 240s at about 1350 fps. Believe they were sized to 0.432 as the 44 Mag rifle has a different chamber than the 44 mag pistol. Why SAAMI allowed that is beyond me.