• Watch Out for Scammers!

    We've now added a color code for all accounts. Orange accounts are new members, Blue are full members, and Green are Supporters. If you get a message about a sale from an orange account, make sure you pay attention before sending any money!

Upcoming LRI Buid: What Reamer to use for 300 Win Mag?

LongRangeJunky

Private
Supporter
Full Member
Minuteman
Feb 19, 2017
766
257
About to send my 700 long action to Long Rifles Inc. for a 300 win mag build.
They have a variety of reamers available. I don't want to call and pester them, and I am not 100% certain I can ascertain the exact answer myself. Figured I'd ask here.

I want to shoot heavy factory ammo. 190-200 grain+, and reload the heavier stuff like the 220 ELDX bullets of which I have some.
If there is reamer spec that is a good 'middle ground' in case I do want to shoot something a little lighter?

Which reamer should I be going with?
I see they have a:
- 300 Winmag MK248-MOD-1 (LAM)
- 300 Winmag Match (LAM)

Also, should I stick with 1.10 twist, or are guys favoring 1.9 for this application these days?

Thank you!
 
Why not email this exact information to Chad and he'll recommend which reamer to use.
I should clarify that I am wondering what other reamer specs are out there other than the two I see listed by LRI's website as available - If any are worth considering.
 
About to send my 700 long action to Long Rifles Inc. for a 300 win mag build.
They have a variety of reamers available. I don't want to call and pester them, and I am not 100% certain I can ascertain the exact answer myself. Figured I'd ask here.

I want to shoot heavy factory ammo. 190-200 grain+, and reload the heavier stuff like the 220 ELDX bullets of which I have some.
If there is reamer spec that is a good 'middle ground' in case I do want to shoot something a little lighter?

Which reamer should I be going with?
I see they have a:
- 300 Winmag MK248-MOD-1 (LAM)
- 300 Winmag Match (LAM)

Also, should I stick with 1.10 twist, or are guys favoring 1.9 for this application these days?

Thank you!
If you are having LRI build you a complete rifle, you wouldn't be "pestering" by asking for guidance.
You for sure will be pestering if you drag them through the weeds trying to consider 100 different 300WM reamers only to possibly still make a poor decision.

Tell them what ammo or bullets you plan to run.
Let them pick the best reamer they believe will serve you best since they are the ones accountable for the rifle shooting accurately.
Ditto for twist rate.

If you take too much of the specs out of my control, I wouldn't stand by any accuracy or performance guarantees at all. I wouldn't expect LRI or any other custom builder to do any differently.

./
 
Well I did not want this to turn into a time drain for anyone, or 'they don't answer the phone' thread.

Just wanted to see if there was a recommended or go to reamer that The Hide recommends for this application.

I'll call or email them.
 
Lri has chambered many barrels for me including 300win mag. Put together a dummy round with your intended bullet seated where you want it(boat tail just at neck shoulder junction) send it in with your component’s with a note telling them everything you want done to barrel, and they will throat out the chamber to your dummy round . Cant be any easier
 
Well I did not want this to turn into a time drain for anyone, or 'they don't answer the phone' thread.

Just wanted to see if there was a recommended or go to reamer that The Hide recommends for this application.

I'll call or email them.
I don't have a 300 Win Mag and probably never will. If I was going to have one chambered I would want them to use a Rhian Mantha reamer.
 
  • Like
Reactions: DIBBS
If you are having LRI build you a complete rifle, you wouldn't be "pestering" by asking for guidance.
You for sure will be pestering if you drag them through the weeds trying to consider 100 different 300WM reamers only to possibly still make a poor decision.

Tell them what ammo or bullets you plan to run.
Let them pick the best reamer they believe will serve you best since they are the ones accountable for the rifle shooting accurately.
Ditto for twist rate.

If you take too much of the specs out of my control, I wouldn't stand by any accuracy or performance guarantees at all. I wouldn't expect LRI or any other custom builder to do any differentl

When I had Dave Tooley build my 300 WinMag he asked what ammo I was planning on using. Told what bullet I was using and it’s probably one of my most accurate rifles.
 
  • Like
Reactions: Terry Cross
Call LRI. I've spent enough cash with them to know that a 5 minute discussion is saving you from years of ass pain and headaches.
 
300WM stuff:

in 2012 I got involved with a little research project for the DoS. An incident had occurred that gave them cause to look at a precision gun capable of more reach than the 308/7.62 that they'd had for years. (M24s) Parallel to this, some forensic accounting had taken place, and it was realized that the 338LM was costing the US taxpayer an absurd amount of money. Around $25/$30 bucks a round by the time you factor in all the logistical hurdles to get it in theatre. An alternative solution was initiated.

The MK248 Mod-0 with the 190-grain bullets had been around for a while. Crane and Lake City put their heads together, and the Mod-1 was born. Nothing more than a juiced-up 300WM running the 220 Sierra. The issue was the guns. The ones originally built by Crane had pressure issues. Folks using them were carrying dead blow mallets to beat the bolts open due to pressure. As a result, those guns were left in the cases as they were essentially useless.

State was curious about adding the platform to their DDM lineup, and I was asked to try and help by sorting out the pressure issue. Some creative throating and neck diameter work solved it. It looked like we were going to get a sugar of a deal, but it tanked when a purchasing agent at State bought a pile of M700s in 338LM. They found out the hard way that it was a bad idea, and it left a taste in their mouths that stopped any further momentum.

We were grateful for the opportunity as it taught us a lot. We've fitted these up for guys who successfully pushed a 220 Sierra north of 3200fps. At that velocity, the ballistic behavior almost duplicates the 338LM loaded with a 250 Scenar. The advantage is you get 3-1/2 more rounds per lb of ammo carried (A big deal if you are a secret squirrel guy), and you're doing it for pennies on the dollar of what the 338LM costs.

Hope this helps.

C.
 
300WM stuff:

in 2012 I got involved with a little research project for the DoS. An incident had occurred that gave them cause to look at a precision gun capable of more reach than the 308/7.62 that they'd had for years. (M24s) Parallel to this, some forensic accounting had taken place, and it was realized that the 338LM was costing the US taxpayer an absurd amount of money. Around $25/$30 bucks a round by the time you factor in all the logistical hurdles to get it in theatre. An alternative solution was initiated.

The MK248 Mod-0 with the 190-grain bullets had been around for a while. Crane and Lake City put their heads together, and the Mod-1 was born. Nothing more than a juiced-up 300WM running the 220 Sierra. The issue was the guns. The ones originally built by Crane had pressure issues. Folks using them were carrying dead blow mallets to beat the bolts open due to pressure. As a result, those guns were left in the cases as they were essentially useless.

State was curious about adding the platform to their DDM lineup, and I was asked to try and help by sorting out the pressure issue. Some creative throating and neck diameter work solved it. It looked like we were going to get a sugar of a deal, but it tanked when a purchasing agent at State bought a pile of M700s in 338LM. They found out the hard way that it was a bad idea, and it left a taste in their mouths that stopped any further momentum.

We were grateful for the opportunity as it taught us a lot. We've fitted these up for guys who successfully pushed a 220 Sierra north of 3200fps. At that velocity, the ballistic behavior almost duplicates the 338LM loaded with a 250 Scenar. The advantage is you get 3-1/2 more rounds per lb of ammo carried (A big deal if you are a secret squirrel guy), and you're doing it for pennies on the dollar of what the 338LM costs.

Hope this helps.

C.
How was this achieved? or is it proprietary? I have an action and was thinking of a long 300 Winchester.
 
I recently chambered a rifle in 300 Win Mag for a customer wanting to be able to shoot 215gr Burgers and factory ammo on occasion as he was learning to handload. I did some digging and found that PTG made a reamer for McMillan used in the Chris Kyle series of rifles. The reamer was in stock and on the shelf. It has a tighter neck than SAAMI and the freebore is held to .0006” and is plenty long to get 215’s in the case without extending to far into capacity.
 
I recently chambered a rifle in 300 Win Mag for a customer wanting to be able to shoot 215gr Burgers and factory ammo on occasion as he was learning to handload. I did some digging and found that PTG made a reamer for McMillan used in the Chris Kyle series of rifles. The reamer was in stock and on the shelf. It has a tighter neck than SAAMI and the freebore is held to .0006” and is plenty long to get 215’s in the case without extending to far into capacity.
What was the freebore length on that reamer? I have a 308 Norma Mag reamer that was made for 215 gr Bergers. I would like to see how it compares to that one.
 
We've fitted these up for guys who successfully pushed a 220 Sierra north of 3200fps. At that velocity, the ballistic behavior almost duplicates the 338LM loaded with a 250 Scenar. The advantage is you get 3-1/2 more rounds per lb of ammo carried (A big deal if you are a secret squirrel guy), and you're doing it for pennies on the dollar of what the 338LM costs.
I’ve never wanted a 300WM before but this gets me wet.