.308 Sierra GameKing rookie questions

[Borcha]

Hello folks. I rarely start topics on any forum and this is my first post so apologies for clutter. It looked more appropriate than tacking my question onto another thread. As very quick background I am not at all an expert shooter or handloader but I have always been interested in both and this past year have been ramping up the loading end with a fairly nice setup and have been soaking up as much as I can.

The first rifle I ever purchased back in the 90's is a Ruger MKII .308 nothing special poly rifle. Its a relative cheapo but over the years its helped thwart many barn and chicken coop attacks by various assailants and it has some sentimental value to me so I've started working on it some with a decent optic, cleaning, and quality ammo to pay it back for years of relative neglect. I got some poly tipped Sierra GK bullets, prepped some brass, 4064 powder and figured out what to shoot for as far as bullet seating depth. The first one I put in the rifle to make sure it felt like it chambered well, it did so my goal was to assemble 5 rounds and see how everything felt and performed. So I went to extract the round and make 4 more and problem..... the cartridge is too long to extract. The GK bullets are fairly long and narrow compared to the other ones I've used (Speer mostly) successfully and the tip can't quite make it by the frame to get out. I needed to open up the floorplate and struggle it out the bottom manually. Due mostly (I think) to the thin tip my COAL, even after setting the bullet deeper, is 2.9655 which is obviously well over the max .308 COAL of 2.810 listed in my Speer book.

So my two part question is

1) Interested in thoughts on these green tipped Sierra bullets. Is it ok to just back the bullet well back off the lans until it can be extracted without sacrificing most of the advantages of careful handloading for this firearm? Or what would/do you guys do when faced with this dilemma and

2) I'm planning on purchasing a decent rifle to really spend some time handloading for and had targeted a Bergara premier approach rifle in 7mm-08. That rifle has a detachable box mag and now I'm wondering if that might be something best avoided for a handloader hobby type rifle. Bergara makes a similar model called a Highlander or something that has a hinged floorplate internal mag. I like the looks of the Approach rifle but I'm wondering if that magazine is going to limit my hand loading career? Guidance/opinions would be greatly appreciated.

 

[Blue68f100]

I always start at recommended length that the mfg suggest. With SGK & MK's I've always had excellent results. As you found out the round has to fit the magazine. too. A lot of guns these days have very long leads. And a lot of bullets do fine with 0.050"-0.100"+ jump. Shorten them so they fit the go test.

 

[ArchAngelCD]

Welcome to the forum. Maybe a different bullet instead of changing your rifle choice. Sorry that is probably not what you want to hear.

 

[Cheesemaker]

Check the Sierra manual (not Speer) for the specs on that bullet. Your COAL seems quite long.

....Due mostly (I think) to the thin tip my COAL, even after setting the bullet deeper, is 2.9655 which is obviously well over the max .308 COAL of 2.810 listed in my Speer book.....

 

[stillquietvoice]

Welcome to the forum. What is your distance to the lands? 2.9655 sea really long. How much of the base is in the case. If there's not enough base in the neck there may not be enough tension to keep the bullet in your case under recoil. If you need them long a distance between mag length and being completely able to remove unifired cartridge will best fit your needs. Male your Max oal so it will extract.

 

[Slamfire]

1) Interested in thoughts on these green tipped Sierra bullets. Is it ok to just back the bullet well back off the lans until it can be extracted without sacrificing most of the advantages of careful handloading for this firearm? Or what would/do you guys do when faced with this dilemma and

If you don't have a Hornady OAL case gauge




then you can take a magic marker, blacken the bullet, and seat the round hard, and see if there are rifling marks. If there are, seat the bullet deeper until you see no rifling indentations on the bullet. Seat the cartridge hard because there is drive in, that is slight clearance between the lugs and the barrel end. You want to take that up. Few things are more upsetting than having a bullet lodged in the throat, powder spilling out in the action, and not having a cleaning rod to knock the bullet out. I have been a friend of many at mid range and long range matches because my scope stand has a cleaning rod inside the long tube

 

[Borcha]

I do have the Hornady gauge as well as a few other devices. That is what I used to set the bullet in the modified case initially and then I backed it off some and still wasn't even close to being able to clear the rifle with the bolt (removing an unfired round I mean... it chambers and I assume will shoot just fine although I haven't shot one yet).

I think the discrepancy is the shape of the 165gr gamechanger bullet itself. From base of boat tail to end of green poly tip I get 1.3815 same measurement with a Speer 165gr boat tail I get 1.215. Using the Hornady comparator gauge on the calipers with the 7-28 insert I get 2.323 on some handloaded rounds I did awhile back that shot great. With my green tipped Sierra gamechangers that I had to back off (I mean seat the bullet deeper) a mile from I wanted to do I only measure 2.266 even though the overall cartridge is considerably longer. The Speer will extract with no problem, the Sierra I basically have scraping the tip across the frame of the ejection port or whatever that is called. And also the bullet is definitely seated in the case enough. I think I might even be slightly compressing the powder currently. I didn't get a measurement just now but its "way in there" for sure.

Appreciate the responses to give me some ideas to consider/mull over. Running into this issue had just gotten me to thinking that if I want to strive for (relatively) precise hand loads maybe on the new rifle I intend to purchase a detachable magazine might actually cause more of these kinds of problems. As part of my hand loading education I've watched a billion youtube videos and I remember on several occasions seeing mention of how this or that cartridge barely fit in the mag, or in some cases doesn't fit and the rounds have to be top-loaded into the rifle one at a time. I'm not a huge hunter but hope to do more of that in the future and obviously that's not ideal. I'm wondering if maybe I ought to avoid a detachable mag if the whole point of the gun is to craft hand loads for it.

 

[CptnAwesome]

Look up load data for Sierra GameChangers, not GameKings. Two different bullets and the GameChangers (the ones I've seen anyway) are quite a bit longer than Gamekings.

 

[Walkalong]

The best, most foolproof way to find the lands. It can also be used to set up a sizer.
Sierra bullets tend to make the jump very well, and it's a hunting load. Forget about chasing the lands.

Welcome to THR


I like the Sinclair comparator with inserts for getting the base to ogive measurement,
or the shoulder position related to the base, for the 6 Creed I use the 6MM insert and
the 30 degree insert. It is easy to use and a reasonable price. Hornady makes the same basic thing, but their inserts are aluminum vs SS.

Shown with 6MM insert in too, .22 insert, & 30 degree insert.

 

[Nature Boy]

When trying to eject a round that’s too long for the ejection port just hit the bolt release and pull the round out with the bolt.

Now, regarding the 165g Sierra Game Changers. They are really long and represent the recent trend of bullet makers designing high BC hunting bullets (Hornady ELD-X, Berger VLD Hunting to name some others). The problem is in order to get them to fit the magazine or your action you have to seat them deep, often with most of the bearing surface inside the case.

Sierra’s recommended OAL with the 165 TGK is 2.800. Seat one to that depth and you’ll see that that puts the ogive well into the neck.

Bottom line for me: I wanted to like these, tried 3 times to find an acceptable load but never could get them to shoot in my .308 unless I turned my repeater into a single shot.

Here’s my thread on it

https://www.thehighroad.org/index.php?threads/sierra-308-gamechangers-and-some-others-now.843851/

 

[Borcha]

Nature Boy I appreciate that link to your thread very much. More than you might suspect in fact. I walked all over the same ground and made the same findings/problems/conclusions you did but being still early on in the learning curve I figured I must be missing something or doing something wrong. I guess in some ways this stuff isn't rocket science. If something measures longer.... its longer. When it comes to overall length with these bullets to quote you "theres no friggen way" lol!

On the bright side I guess there are a ton of other bullets out there to try.

 

[Random 8]

Some simple truths. Unless you are shooting extreme ranges, you will see little to no benefit from any of the ELD designs... Sierra GC, Hornady ELX, Nosler LR, etc. They can be more fussy to find loads for in fact than conventional cup and core bullets or "shorter" designs such as the Nosler BT and Hornady SST.

OAL needs first and foremost to fit your rifle if you intend it to be a repeater. The Sierra GCg is relatively new. Not sure if you will find any dedicated data for it. That said, you can use other 165 grain data with the caveat that you will need to seat your bullets more deeply into the case. This will likely increase pressure vs. bullets of the same weight that may be seated less deeply and still function your magazine. Reduce loads and work up with best practices.

In the .308, there is really no reason to look past conventional cup and core SP bullets for deer sized game, or the 155 or 168 HPBT (pick your maker, they're all good) for target shooting to moderate ranges under 400 yards. I shoot A LOT of 155 Noslers through a 7,5 Swiss at basically .308 ballistics at the very challenging 300m INT target every year.

As for jazzing up your rifle, I've never liked pretty girls that are headcases. Give me a plain gal that knows how to cook any day. If your rifle shoots to your requirements, keep shooting it. If not, and a reasonable amount of tweaking won't get you there, I hear Sako and Tikka make a fine product these days.

Edit to add thought on detachable vs internal magazine. You will find no general difference, between the 2, but individual rifles may cause you difficulty if they feature a shorter magazine, and this can occur with either type. Remington rifles in 7mm-08 were known for short magazines in both fixed and detachable. Don't know if they've remedied the issue, I'm just repeating what I read in a reloading manual some years ago. Only knowing the dimensions of the magazine of said rifle and the maximum COL to zero freebore per bullet will give you some starting points, and unfortunately this is impossible to do without the rifle in your hands, although some rifles are known to have longer magazines. A question in rifle country forum could get you some answers on that question per your model in question and others.