.300 Lapua Mag.

[460wby]

I'm playing with this thought.......
Can anybody tell me what to expect from this round, accuracy and velocity -vice?

Comments, please!

 

[Fiftydriver]

460Wby,

The last 338 Lapua brass I measured for volume held 116 gr of H-BLC2 filled to the case mouth.

The 300 RUM filled the same way held 117 gr of teh same H-BLC2.

If the 338 Lapua is necked down I would imagine its volume would be in the 114-115 gr capacity area.

Unless you improve this round, the full length 300 RUM will be a ballistic twin of the round and much cheaper to load for.

I admit that some brass may be larger in case volume then others, the ones I measured were once fired Lapua hulls.

All in all you would have 300 RUM performance.

Good Shooting!!

Kirby Allen(50)

 

[Guest]

Yeah, but the Lapua gets that capacity with - what? - 3.72"? If they're both limited to 3.6" COL the Lap may well have the edge.
And If you have the action for it, then why not go ahead and improve the thing? It's got the taper of an assault round for crying out loud!
If you're looking at heavy/long pills, they're going to plunge into that powder room in the RUM case; not so much in the Lap.

 

[Guest]

According to RCBS.load software, the two cases, loaded to 3.6" COL with a 1.4" long bullet, the RUM case has about 97g of water below; the Lapua has about 103g.
The way I drew the case is by simply necking down, then bringing the top of the shoulder back to the 30* point, leaving the body the same length. Of course, you could move the shoulder forward as well. And you can gain 3.5g simply by taking that "excess " taper out. By doing that, then moving the shoulder to the point of the RUM, you get a little over 116g

!
So, it depends on what you want to do.

But to back up a bit, I would look at your rifle, how long a bbl you're thinking of, which bullet you want to shoot, and check out the RUM's ballistics. Their's faster out there, but it is a screamer as-is. And much cheaper than custom reamers, dies, Lapua Mag cases, etc.

 

[Fiftydriver]

460Wby,

I will be building a 300 Kahn this winter or spring for a customer, what would you think about that round.

Brass is a bit cheaper then the Lapua, they can both be used in the same actions and teh Kahns capacity is totally out of the league of either the RUM or Lapua or Lapua Imp.

I am getting 3100 fps with my 338 Kahn with a 300 gr Wildcat ULD bullet.

I expect the 300 version will get very close to the same with the big 250 gr Wildcat ULD.

Recoil is greatly increased over the smaller rounds though. My 25 lb unbraked 338 Kahn feels alot like my 35 lb 50 BMG with its brake. They are both pretty lively.

Good Shooting!!

Kirby Allen(50)

 

[älg]

you can check vitahvuori´s page and there you will see some theorical loads for the 300 lapua mag.

 

[subsonic]

S1 has created a round called the 300Wolf that is basically a improved 300Lapua its performance with heavy 30 bullets is quite impressive.

 

[BountyHunter]

For the life of me I cannot figure out why someone will build a custom gun with $500 barrel (blank and chambering) talk about pennies on brass.

Brass is the cheapest component in a custom system. Do not be stupid and scrimp here.

Buy the best brass that is available. 100 pieces of 338 Lapua is only $130 from Sinclair and that is full retail. It can be found cheaper. 100 pieces of lapua will outlast two barrels.

I am tuning a 30 hart (300 Weatherby improved) right now for someone now and they have Rem brass. the loads for the Rem brass are blowing primer pockets on 10-20% of the cases and that is backed down. I have wasted time, money and still going to have to order decent brass.

When you build a custom gun, brass should be part of the equation for chambering and setup. Buy either Lapua, RWS (best if you can get it) or Norma.

In my opinion, Rem brass in a custom gun is like a Yugo engine in a NASCAR body.

Well off my soap box now.

BH

 

[sdiehn]

I know of a guy who played around with this cartrige in the early 70`s and gave up on it because of throat errosion true accurate life of the barrel was under 1000 rounds no matter what he tryed and he makes barrels