Anyone own a 7mm 300 Win Mag?
- Thread starter Broz
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New Alberta guy here! Bighorn35
Sure have an interest in this caliber. Want to build a reasonably light sheep rifle. Currenting shooting a Custom 300 Wby built by the late great David Gentry. Super rifle both in quality and performance.
Would like to know from you guys about these stats and what could be expected and or changed. 700 or custom action, Brux #4 fluted barrel (24-25") contuored brake 9 twist (possibly 8.5) McMillian sporter stock,jewel trigger. Want to shoot 154gr Interbonds. As a hunter and former outfitter have had tremendous success with Hornady.
Would appreciate comments from your experience from fellas like Broz, Kiwi Nate and others.
I would like to leave shoulder angle normal and just size case in one operation,with no fireforming. Also want a no turn neck.
I'm not interested in bullets any heavier than 162 gr as the 300Wby fills the big needs.
What kind of throating am I going to need and what aproximate velocities do you think can be expected. Will there be enough gain over 7mm RemM.
Thanks
No long freebore like the Wby's
Sure have an interest in this caliber. Want to build a reasonably light sheep rifle. Currenting shooting a Custom 300 Wby built by the late great David Gentry. Super rifle both in quality and performance.
Would like to know from you guys about these stats and what could be expected and or changed. 700 or custom action, Brux #4 fluted barrel (24-25") contuored brake 9 twist (possibly 8.5) McMillian sporter stock,jewel trigger. Want to shoot 154gr Interbonds. As a hunter and former outfitter have had tremendous success with Hornady.
Would appreciate comments from your experience from fellas like Broz, Kiwi Nate and others.
I would like to leave shoulder angle normal and just size case in one operation,with no fireforming. Also want a no turn neck.
I'm not interested in bullets any heavier than 162 gr as the 300Wby fills the big needs.
What kind of throating am I going to need and what aproximate velocities do you think can be expected. Will there be enough gain over 7mm RemM.
Thanks
No long freebore like the Wby's
Stonewall2
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backwoods83
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Mos people that go with a 7x300wm do away with the body taper and go to a 35 degree shoulder this leaves you with a 5 grain powder capacity disadvantage to the 7mm stw but it also gives you the more efficent shoulder advantage over the stw. by the time its all said and done it should be within 75fps of the stw with less recoil and a little longer barrel life, using less powder means killing less barrel.
Kiwi Nate
Well-Known Member
Hi Bighorn35, sorry for the late reply, have been away hunting.
Ok, nothing wrong with your proposed shoulder angle, means you can make use of a wider range of neck dies than my 7mm Practical.
You made a comment about wanting to avoid fireforming. By necking down from .300 to 7mm, the first load will be a fireforming looad regardless. This load will headspace partially off the belt and partially off the shoulder- depending on the reamer tolerances. Ive detailed all my findings on my website- 7mm Practical article. With belted mags, the belt is a great aid to fireforming, I have shot game out to 1100 yards with foreforming loads (by mistake). My fireforming loads usually go .5" while fireformed loads group .275". I don't use any special mild loads for fireforming. Fireforming is a chance to use up old powder and cheap bullets or just go straight ahead and use your normal accuracy load, perhaps limiting shots with the fireforming load to say 600 yards to be on the safe side (I have a client who does this).
Mine is a no neck turn either. No problems there.
I am not 100% sure you will be happy with the InterBond at long range. Once it gets down to 2100fps, it has a hard time expanding beyond 9mm. You wouldn't want to hunt with a Glock and FMJ ammo so I am sure you won't want to be limited in this regard. The Interbond is great out to 300 yards but as this is a long range forum, I will assume that you will want to hunt out to long ranges and utilize a bullet that will get the job done nicely at lower velocities. To this end, if you are a great fan of the InterBond, try the 154gr SST as a start point. You can then use the two projectiles (same form and form factor) interchangeably- one for woods hunting tougher animals, one for open country work. Again, I have plenty of notes on all of this stuff online if you want to take a bit of time to research it all. Another good bullet you may like to consider is the 162gr SST, its a very good allrounder, fairly high BC for a controlled expanding bullet. Downside of the SST and IB is they they can be a finnicky to load, some rifles have trouble with them and it can cost a lot (plus time) to obtain a sweet spot. Patience and flexibility are key.
I don't have a long throated rifle. Bullet jump is 40 thou, I don't much like the 400 thou jump that is popular at the moment. If you really want some freebore, you could copy the .308 Winchester design and have say around 100 thou jump- just as an example.
Ok, hope that helps get you started. You should be able to duplicate my velocities regardless of shoulder angle.
Nathan.
Ok, nothing wrong with your proposed shoulder angle, means you can make use of a wider range of neck dies than my 7mm Practical.
You made a comment about wanting to avoid fireforming. By necking down from .300 to 7mm, the first load will be a fireforming looad regardless. This load will headspace partially off the belt and partially off the shoulder- depending on the reamer tolerances. Ive detailed all my findings on my website- 7mm Practical article. With belted mags, the belt is a great aid to fireforming, I have shot game out to 1100 yards with foreforming loads (by mistake). My fireforming loads usually go .5" while fireformed loads group .275". I don't use any special mild loads for fireforming. Fireforming is a chance to use up old powder and cheap bullets or just go straight ahead and use your normal accuracy load, perhaps limiting shots with the fireforming load to say 600 yards to be on the safe side (I have a client who does this).
Mine is a no neck turn either. No problems there.
I am not 100% sure you will be happy with the InterBond at long range. Once it gets down to 2100fps, it has a hard time expanding beyond 9mm. You wouldn't want to hunt with a Glock and FMJ ammo so I am sure you won't want to be limited in this regard. The Interbond is great out to 300 yards but as this is a long range forum, I will assume that you will want to hunt out to long ranges and utilize a bullet that will get the job done nicely at lower velocities. To this end, if you are a great fan of the InterBond, try the 154gr SST as a start point. You can then use the two projectiles (same form and form factor) interchangeably- one for woods hunting tougher animals, one for open country work. Again, I have plenty of notes on all of this stuff online if you want to take a bit of time to research it all. Another good bullet you may like to consider is the 162gr SST, its a very good allrounder, fairly high BC for a controlled expanding bullet. Downside of the SST and IB is they they can be a finnicky to load, some rifles have trouble with them and it can cost a lot (plus time) to obtain a sweet spot. Patience and flexibility are key.
I don't have a long throated rifle. Bullet jump is 40 thou, I don't much like the 400 thou jump that is popular at the moment. If you really want some freebore, you could copy the .308 Winchester design and have say around 100 thou jump- just as an example.
Ok, hope that helps get you started. You should be able to duplicate my velocities regardless of shoulder angle.
Nathan.
Broz
Well-Known Member
One of the nice things about using the case and shoulder dimentions of the 300 win case as they are is, dies. We are simply using a redding bushing dies to size the cases down by starting with a larger bushing and downsizing until we have .002 or .003" of neck tension. The after fireformed it is a one step pocess to size. We also have a redding 300 win body die for when the case or shoulder needs a slight sizing. Nice to be able to get the dies off the shelf from many sources too.
I have just started a build on another 7mm-300 Win. This one is for another friend and will be a lighter weight lefty. Found an early 700 Rem action (no J lock) and have a Hart 6 land barrel with Sendero contour and 6 1/4" flutes on order. Now I need to find the perfect lefty stock. The selection is a bit slim and the waits from Manners or McMillan didn't excite me much.
Jeff
I have just started a build on another 7mm-300 Win. This one is for another friend and will be a lighter weight lefty. Found an early 700 Rem action (no J lock) and have a Hart 6 land barrel with Sendero contour and 6 1/4" flutes on order. Now I need to find the perfect lefty stock. The selection is a bit slim and the waits from Manners or McMillan didn't excite me much.
Jeff
Weaselthis
Well-Known Member
Finally, the reamer came in and the rifle is ready for pickup this weekend!
I've loaded up 50 brand new Nosler 300WM brass w/ some H4350 and 154g Hornadys that I have lying around. Seated them to the cannelure. Then had a thought.
I purposely seated my .280AI long for the initial fireforming load w/ factory 280 Rem. ammo. Banged em out w/ an inertia bullet puller and re-seated them to .0200 into the lands.
So, question for those of you in the know: Do you think I should/MUST seat these INTO the lands as well, or will the shoulder/belt provide enough support to fireform these? I don't mind doing the extra step to accomplish this, but wanted to hear if any of you did seat long or is it a waste of time?
Thanks guys!
I've loaded up 50 brand new Nosler 300WM brass w/ some H4350 and 154g Hornadys that I have lying around. Seated them to the cannelure. Then had a thought.
I purposely seated my .280AI long for the initial fireforming load w/ factory 280 Rem. ammo. Banged em out w/ an inertia bullet puller and re-seated them to .0200 into the lands.
So, question for those of you in the know: Do you think I should/MUST seat these INTO the lands as well, or will the shoulder/belt provide enough support to fireform these? I don't mind doing the extra step to accomplish this, but wanted to hear if any of you did seat long or is it a waste of time?
Thanks guys!
Kiwi Nate
Well-Known Member
Hi, use the belt, it will be just fine, gives the belt a purpose. Thats one of the advantages of basing a wildcat on a belted mag. Looks like you will be having a lot of fun over the next few weeks.
Weaselthis
Well-Known Member
THANK YOU, Sirs!
Gonna be "chilly" in sunny CA this weekend, but the bbl. will keep me warm!
I will post the results of the workup w/ a variety of bullets/powder.
Gonna start w/ H1000 & Retumbo and 180g Bergers, 168g Bergers, 160g Accubonds, 160g Barnes, & 160 Partitions. See how they shoot. I have some 140g Bergers & Partitions, but want to try the heavier ones first.
IF this take off bbl. shoots, I'll keep it. (Got it cheap). If not, I have a new Bartlein on order an go from there. This is going to be a "hunter" and not a competition rifle, so I want to try a variety of hunting bullets that have proven themselves in the past. (Been a "Partition Peoples" for 25+ yrs.).
One thing's for sure....gonna be fun.....gonna get a sore shoulder....and SOMEONE is losing a trailer house.....lol oops....wrong state/joke....
Gonna be "chilly" in sunny CA this weekend, but the bbl. will keep me warm!
I will post the results of the workup w/ a variety of bullets/powder.
Gonna start w/ H1000 & Retumbo and 180g Bergers, 168g Bergers, 160g Accubonds, 160g Barnes, & 160 Partitions. See how they shoot. I have some 140g Bergers & Partitions, but want to try the heavier ones first.
IF this take off bbl. shoots, I'll keep it. (Got it cheap). If not, I have a new Bartlein on order an go from there. This is going to be a "hunter" and not a competition rifle, so I want to try a variety of hunting bullets that have proven themselves in the past. (Been a "Partition Peoples" for 25+ yrs.).
One thing's for sure....gonna be fun.....gonna get a sore shoulder....and SOMEONE is losing a trailer house.....lol oops....wrong state/joke....
Broz
Well-Known Member
Nate, I am in the process of another 7mm-300 build. I am now designing the reamer for this build which will be for a friend. I plan to leave the case basically the same with the 25 degree shoulder and set the bullet .040" off the lands when you seat a 180 Berger so the top of the boat tail is even with the bottom of the neck. This should give me a full .200" of bearing surface into the neck. Also the lead angle of the rifling would be about 1 1/2 degree. I am interested in hearing your opinion on this?
Thanks!
Jeff
Thanks!
Jeff
Kiwi Nate
Well-Known Member
The lengths you are looking at are similar to mine but possibly more geared solely towards the 180gr VLD. My COALS listed on our site, are geared towards the best balance for the 162gr SST, 162gr A-Max, 168gr VLD and 180gr VLD. ou can use the 168gr VLD as the base for the throat design (length), flush with the neck shoulder junction, all other bullets work well thereafter. I had to make mine somewhat flexible with bullet designs as my clients often have their own favorite bullets, the SST being one example.
I generally use 40 thou jump too. I don't often get finnicky performance with bullet jump as I am pretty tough on focusing on the rifle itself as the most influencial factor. A good action, good bedding, good barrel and good monitoring of fouling etc and good shooting technique are my high priorities. If the these jobs are done right, hand loads should not be finnicky and with care, a custom build will give sub .5MOA accuracy. All of the 7mm-300's I have done so far group under .3" without fuss regarding handloads although changes in powder charges do of course have a dramatic effect on accuracy. I can't emphasize enough the importance of the rifle as a platform and all of the subtleties involved to that end.
I generally use 40 thou jump too. I don't often get finnicky performance with bullet jump as I am pretty tough on focusing on the rifle itself as the most influencial factor. A good action, good bedding, good barrel and good monitoring of fouling etc and good shooting technique are my high priorities. If the these jobs are done right, hand loads should not be finnicky and with care, a custom build will give sub .5MOA accuracy. All of the 7mm-300's I have done so far group under .3" without fuss regarding handloads although changes in powder charges do of course have a dramatic effect on accuracy. I can't emphasize enough the importance of the rifle as a platform and all of the subtleties involved to that end.
Broz
Well-Known Member
Agreed, I have a SS Hart Sendero Contour with 6 1/4" flutes in a 9 twist comming. Hart will flute then final hand lap the tube and re-stress relieve it. I am still fighting with myself on barrel length. I have always done 28" but feel he need to try a 26" so I had it fluted to go sither way. Maybe a 27" is in order for this one..
Thanks
Jeff gun)gun)
Kiwi Nate
Well-Known Member
Gotta love those Hart Barrels, tack drivers.
Yes, I need to build a 26" barreled version one day also, a lot of guys want to see the actual rather than theoretical results of the cartridge when a 26" barrel is employed. A few want to know what a 24" barrel would be like- not for true LR hunting, just for normal hunting out to say 400 yards. Others want to know what a welter weight barrel would do.
Yes, I need to build a 26" barreled version one day also, a lot of guys want to see the actual rather than theoretical results of the cartridge when a 26" barrel is employed. A few want to know what a 24" barrel would be like- not for true LR hunting, just for normal hunting out to say 400 yards. Others want to know what a welter weight barrel would do.
