Lapua 90gr. 6mm Scenar?

[flatlander]

I'm getting started on a new 6mm project - an AR15 spacegun upper chambered for the 6mm HAGAR,Harrison And Goodling Auto Rifle). The cartridge is based on the 30 Rem. case - with a case length of 1.770", it's longer than the 6.8 SPC, but shorter than the full-length 30 Rem. In the photos I've seen, it looks kinda like a 223 on steroids. Case capacity is around 1.5-2grs. less than a Dasher, so 2850-2900fps would seem to be a reasonable velocity to expect with 105-107gr. bullets out of a 28" bbl.

The question I have concerns Lapua's 6mm 90gr. Scenar - I'm thinking of trying it for prone rapids at 300yds. John Harrison is shooting Hornady 87BTHPs in his HAGAR at 200 & 300, and is satisfied with his results - I have a few boxes of the 87 BTHPs on hand, so intend to try them. I've shot them against the 87 VMax out of one of my Dashers, and the VMax's groups are a little tighter at 300. The thing about the 87 VMax is how its plastic tip will handle being fed through the barrel extension of an AR - won't know about that until I try it.

I guess the reason I'm curious about the 90gr. Scenar is that I've gotten such good 600yd. accuracy out of the 105 Scenar in all three of my Dashers, but haven't heard much about anyone using the 90s. I'd also like to try them in the Dashers and a 6x47 Lapua that I've just finished putting together. Anticipated use in those rifles would be BR Varmint Silhouette and mid-range prone HP.
Would appreciate feedback from those of you who've shot the 90s.

 

[fnnm1]

Dennis:

I tried the 90 Scenars in my 6mm AR match gun. For mag long rounds in the rapids, accuracy was not as good as the 105 Berger BT and 105 Amax. I seem to remember that the 90 Scenar was not suitable, in the 6mm AR, for mag long rounds because it was jumping quite a bit compared to the other two. Loaded long it was better but I wouldn't use it at 500/600. So I just used up what I had offhand.

The 105 Amax had been real good in my rifle. They feed just fine. I've had a few really mashed but the red tips stay on now.

Paul

 

[MarkS]

Dennis,

I have shot the 90 gr Berger's at 1000 yds in my varmint gun 6 AI, with a 5.8" group - 9.00" 6 target Agg. I would think the Laupa's would shoot good also.

Mark Schronce

 

[rcw3]

I'm getting started on a new 6mm project - an AR15 spacegun upper chambered for the 6mm HAGAR,Harrison And Goodling Auto Rifle). The cartridge is based on the 30 Rem. case - with a case length of 1.770", it's longer than the 6.8 SPC, but shorter than the full-length 30 Rem. In the photos I've seen, it looks kinda like a 223 on steroids. Case capacity is around 1.5-2grs. less than a Dasher, so 2850-2900fps would seem to be a reasonable velocity to expect with 105-107gr. bullets out of a 28" bbl.

The question I have concerns Lapua's 6mm 90gr. Scenar - I'm thinking of trying it for prone rapids at 300yds. John Harrison is shooting Hornady 87BTHPs in his HAGAR at 200 & 300, and is satisfied with his results - I have a few boxes of the 87 BTHPs on hand, so intend to try them. I've shot them against the 87 VMax out of one of my Dashers, and the VMax's groups are a little tighter at 300. The thing about the 87 VMax is how its plastic tip will handle being fed through the barrel extension of an AR - won't know about that until I try it.

I guess the reason I'm curious about the 90gr. Scenar is that I've gotten such good 600yd. accuracy out of the 105 Scenar in all three of my Dashers, but haven't heard much about anyone using the 90s. I'd also like to try them in the Dashers and a 6x47 Lapua that I've just finished putting together. Anticipated use in those rifles would be BR Varmint Silhouette and mid-range prone HP.
Would appreciate feedback from those of you who've shot the 90s.

Dennis

Based upon what I know of the Lapua 90's and the HAGAR, forget the Lapua 90's as a mag fed bullet from a HAGAR. First off the 90 Scenar is a bullet that does not jump particularly well, and the mag fed bullets in the HAGAR have to jump a lot. Second, the HAGAR case is so long that if you load the 90's mag length, the bearing surface of the bullet will be back in the case so far it will be back beyond the mouth of the case. From the information I have on the HAGAR, but for the fact that the guys shooting the HAGAR cut the fronts off of the magazines so they can load mag length bullets about .050" or so longer for the rapids, even the Hornady 87 BTHP has this issue. Stick with bullets with a real blunt front end in the HAGAR for magazine feeding, and ones that can jump a lot and still shoot. The Hornady 87 gr BTHP is the bullet typically used for the HAGAR because it is one of the few 6mm bullets that can work out dimensionally for magazine feeding. The Hornady 87 gr BTHP is blunt in the front so that when you load it mag length in the HAGAR, the bearing surface of the bullet does not disappear way down into the mouth of the case. When I ran some calculations on the HAGAR, it seemed to me if you load the Hornady 87's at 2.280" as a mag length, they would jump about .180" to the lands, and if you cut the fronts off the magazine and squeak out another .050" and load them out to about 2.330" you jump them about .130" to the lands. This would be with a chambering set up with the HAGAR to shoot a 600 yard load with the Berger 105 VLD's where the junction of the boat tail and bearing surface of the bullet is just ahead of the neck and shoulder of the case,which is how the 6mm HAGAR chamber is set up). I think you'll find most of the real pointy tip bullets wil be a no go for magazine feeding from a HAGAR, including the plastic tip varmint type bullets.

The HAGAR seems to be a great cartridge out of an AR-15 for certain types of shooting, but you need to work within the somewhat narrow parameters of the cartridge case and chambering. It was not designed from the ground up as an all around general shooting cartridge or chambering to use a whole bevy of 6mm bullets,especially if you are going to mag feed them), but it does appear to work well for its intended use,across the course high power competition) with certain bullets,i.e. Hornady 87 BTHP for short lines and mag feeding with the magazine fronts cut off, and Berger 105 VLD single loading for the long line).

Robert Whitley

P.S. Your velocity estimates are aggressive for an accurate AR-15 velocity. Next to impossible to get the accurate velocity from an AR-15 that you would be able to from a bolt gun, so I don't believe your Dasher comparison is workable.

 

[12man]

My new 6 BR is just about done.1-10 twist Lilja barrel with .265 neck Primary use will be varmints,coyotes 100-500 yd. Occassional range work I have some 90 gr lapuas I would like to shoot any suggestions using lapua brass? Also have some 77grain lapua bullets How are they shootong? Thanks D

 

[Forum Boss]

My new 6 BR is just about done.1-10 twist Lilja barrel with .265 neck Primary use will be varmints,coyotes 100-500 yd. Occassional range work I have some 90 gr lapuas I would like to shoot any suggestions using lapua brass? Also have some 77grain lapua bullets How are they shootong? Thanks D

You'll have to neck-turn obviously. A .265 is enough of a reduction that you may want to do two passes. Ken of K&M tools, feels you will get the best results if you run the brass through a conventional body & neck full-length sizing die first, then run the expander mandrel.

The 77 grain Lapua bullets are extremely accurate. Check the diameter at the driving band. Some Lapua bullets run a bit skinny. If you're not satisfied with the Lapuas, try the Berger 80s. They are extremely accurate. For me they performed much better than Hornady 75gr or 87gr Vmax.

 

[12man]

Thanks for the tips already prepped 300 lapua cases while waiting for the rifle to be finished. used a K&M neck turner down to .262. Redding body die & Redding neck sizing die .261 bushing. Is this about right on the neck tension Just looking for loading tips on the lapuas 90 gr/ 77 gr. Should I start at .005-.010 jump? I have varget & n135 in quantity, what about primer suggestions. I also have 80 gr Fowler & Bergers. New to this cartidge, just trying to get advice & a good starting point from people experienced with loading / shooting the 6 BR. I Plan on using wilson die for seating. Thanks D

 

[flyingbair]

Dennis,

I have had extremely accurate groups with the Lapua 90 gr Scenar. Granted I am using it in a 6mm BR AR Match Rifle. My chamber is long so I am jumping these bullets. Of the two rifles we are currently testing we have had the best luck with Lapua 90's for the 200 and 300 yd lines with the bullets seated to magazine length,2.25 inches). We are currently using N540 and getting 3200 fps.

Hope this is helpful.

Johnnie

 

[paulT]

Jonnie, would vit n540 be good for load developement in my 1 in 8 and 1 in 10 twist 243 barrels shooting either the 90 molly scenars or 95 and 105g molly bergers in my 243, ifso what prms would suit the vit powder, thanks paul.

 

[flatlander]

Wow - I started this thread almost 20yrs ago...and the 6 HAGAR that I built shot pretty decently in XTC HP matches, though I thought it was tough to find short line loads that shot as good as most of the 223 200-300yd loads that most of us had been loading for years without much load development needed to shoot consistently good X-count cleans. For me, the only really worthwhile advantage over a good 223 AR of either the HAGAR or 6 RAT was with Berger 105VLDs at 600. Looking back in time, all the work I put into making HAGAR brass out of R-P 30 Rem brass was basically wasted time. That brass wasn't designed to stand up to the pressure needed to get decent velocity out of this 6mm wildcat, and primer pockets got loose after 1-2 firings in most of the loads I tried. It wasn't until Hornady started making very good quality HAGAR brass that I got the accuracy I'd been looking for, along with durable cases. Eventually, I just went back to good Krieger 223 28" bbls for AR15 match rifles...

I was looking at some HAGAR cases in the loading room a few days ago, and thinking of getting a reamer ground that would have slightly tighter dimensions, suitable for use in a bolt rifle. If a 6.5 Grendel bolt in a Howa Mini action would give reliable extraction, I'd like to build a 6 HAGAR boltgun...though there's probably not much difference between the HAGAR & 6 RAT that I already have in a Mini...