Gunsmithing 300 rum build

[obilly]

I need to order my barrel for my r 700, 300 RUM. I'm thinking a 1:9 polygonal but I want to hear some thoughts on the matter before I do. This is my one mile build and won’t see anything lighter or faster than a 220 grain VLD. Also any thoughts on a good barrel man for a poly? I already have the gunsmith.

 

[JJones75]

Re: 300 rum build

1-10 twist is plenty for 300RUM , even for 240g SMK's so the 220 will be fine.
I have a had two poly barrles and can't say they are anybetter than a 4-5 groove cut rifled barrel as far as barrle life goes , neither were nearly as accurate as a Bartlein or Kreiger chambered in same cal i've had (308)

I do recomend having a Wyatt's extended mag box installed if you want to shoot long bullets or you will be seating them deap in the case

 

[Deej]

Re: 300 rum build

why a poly barrel?

 

[Goin'Hot]

Re: 300 rum build

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: JJones75</div><div class="ubbcode-body">1-10 twist is plenty for 300RUM , even for 240g SMK's so the 220 will be fine.</div></div>

This is good advise.

 

[obilly]

Re: 300 rum build

Well like I said I'm not settled yet but I was hoping to get extended life and velocity with no diminished accuracy out of the poly. My theory (and someone please correct me if I'm wrong) is that less bullet obturation, more barrel life, more speed and with more speed more range. But I Might go with JJones advice and stick with Krieger 1:10. I wish I had more money to experiment with.

 

[Goin'Hot]

Re: 300 rum build

Have the barrel Salt Bath Nitrided at MMI Trutech in Arkansas.

 

[obilly]

Re: 300 rum build

Any suggestions for a <span style="font-weight: bold">detachable</span> mag?

 

[Goin'Hot]

Re: 300 rum build

Is this going to be a hunting rifle or used for long range target shooting? The reason I ask is, if it's just going to be used for target shooting, have the chamber throated to get the bullet out of the case so you have more room for powder. At that point, you'll actually want a single shot due to cartridge OAL.

 

[Sonic Crack]

Re: 300 rum build

If you run AI 338 CIP mags you can get the bullets seated out good. The 220SMK at a 3.750 COAL has an almost perfect neck shoulder junction. 208 AMax, 210SMK, 240SMK are all not bad at that COAL ether.

 

[Hoge]

Re: 300 rum build

I had Bugholes build me a 300rum. His reamer for it has me at a coal of 3.895 with 208 amax. Have the seekins 338dbm, they fit in it at that length but don't feed as well as I'd like

 

[obilly]

Re: 300 rum build

anyone have good results with the salt bath? worth the money? ie twice the cost twice the life?

 

[Sonic Crack]

Re: 300 rum build

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Hoge</div><div class="ubbcode-body">I had Bugholes build me a 300rum. His reamer for it has me at a coal of 3.895 with 208 amax. Have the seekins 338dbm, they fit in it at that length but don't feed as well as I'd like </div></div>

Are you sure your COAL is correct? Sorry but your not going to fit a 3.895 COAL in any 338 mag, CIP or not

 

[Goin'Hot]

Re: 300 rum build

I had the Seekins 338 dbm on an edge build and wasn't happy with the mags. When it was all said and done, I wished I had made it a single shot. TOF to a mile is around 2.8 seconds. There is NO NEED for a quick follow up shot from a mag. If those are going to be your distances for the rifle, build a ss.

 

[WindDoper]

Re: 300 rum build

Mcmillan uses a schneider poly rifled tube on the EOL series rifles I believe. They are proven shooters. For a 1 mile gun though personally I would do a 338. Check kirby allens stuff out.

 

[Hoge]

Re: 300 rum build

Seekins allows for a 3.9 overall. http://www.seekinsprecision.com/detachable-bottom-metal-163.html

 

[Derrick300]

Re: 300 rum build

One of my all time favorite hunting calibers. My experience has always been dead on impact with the 150g Scirroccos.

 

[xXlojackXx]

Re: 300 rum build

Get any available top barrel brand in a .338 1:9.4" twist and a Wyatt's 4" internal box and change that .300 to a .338 Edge for going a mile. 300gr MK's at 2900fps tastes like chicken!!

 

[Goin'Hot]

Re: 300 rum build

You'll do just fine with the Berger 230's out to a mile with A LOT LESS recoil than the 300 grainers...

 

[obilly]

Re: 300 rum build

Thanks everyone for your wisdom. I think I have settled. R 700, 300 rum with a 30” Krieger 1:10 suppressed on a McMillian a5. With a Wyatt’s extended 5 rd external box. I went with the wyatts instead of the 338 box because I can squeeze a 230 berger hybrid down to a coal of 3.78 and fit the 3.79 box and avoid the feeding issue of the 338 box, it’s a compromise I can live with. I almost went with a single shot but decided at the last possible second that I wanted more flexibility. And as for the 338 edge, I think my rich and famous build will be a 338 Lapua improved mag and I do see that the edge has a slight (ahem) edge. But I need to stay inside a very modest budget and I'm afraid the rum is above my spending limit as it is. (thank God I'm single or I would be after this build) thanks again for all the advice. The people here are among the best in the world hope to see you all at the 2014 SH shoot.

 

[gosooners]

This thread looks dead - but I want to question the requirement to relieve about .25 inch from the rear of the REM 700 action rear bolt stop for the Wyatt DBM. I'm considering a 300RUM project for the new 210 AccuBond LR. It's long, 1.55, so COAL is biggest concern to get into the lands in a DBM repeater.

Thoughts or options on this?