Montana longbow arrows

[grump]

I have a Bear Montana 45#@28 I pull 25" and on bow scale it is 37#@25. For POC arrows what spine and length and point weight would I start with. I used Stu Millers software for aluminium but aluminium just don't fly right from this longbow. I have POC arrows that I think are spined at 50#-55# cut to 28" with 125 grain points that I had for a different bow and they do not work. Also any suggestions if I were to go to carbon? I can shoot a reasonable group (4"@20yard) with my Bear Grizzly so I don't think it is me.
Any and all advice will be much appreciated.

[Jim Dahlberg]

A couple of things come to mind.  What is the fistmele on this bow?  Have you tried changing it drastically?  I think closer to the bow works best for longbows which of course means a longer string.  Have you tried changing the nock point on the string both up and down?  Sometimes a more aggressive approach will make a big difference.  Also make sure your arrow nocks aren't too tight on the string.  That will definitely affect arrow flight.

[nineworlds9]

I've got a 55@28 Montana that I shoot at 28".  It seems to like a pretty tall brace height, around 7-7.5 inches.  Too bad alu's not working for you.  I shoot 29.5" xx75 500 gamegetters out of it with 200g points and get nice groups.  You might try heavier points on those POC's to soften the spine maybe??  Carbon wise you could play with Heritage 90's or 150's and see what happens.

[Reaper TN]

I had a 50# Montana and my draw is 27-27 1/2 inches. It bareshaft tuned perfect with a GT 1535 Trad (.600) arrow cut 29 inches with 175 grains up front.  I think your way overspined at your poundage and draw length, you might try a .700 spine carbon like the CE Predator II shaft. Leave it full length to start with when you begin to bareshaft tune. I agree with 9's, adding more weight to your POC arrows might make them usable. You have to get that arrow bending around the riser for proper arrow flight.

[mcgroundstalker]

A quick fix would be more point weight up front... Try your 50-55 POC with maybe a 200gr. tip.  

[mtnwalker]

what aluminium arrows have you tried in your bow.  have you tried 1816 xx75. I shoot a bear montana longbow #50@28 and draw 27.  1916 at 29 with 125 up front produces great groups.  i can even shoot 2016 @29.5 with 150 up front a get pretty good results. how thick a side plate do you have.

[Mike Mecredy]

With the montanas especially the one of lower wieghts, you can improve how they shoot but cutting the shelf in deeper and putting a radius on it and the sight window.  It's all sort of shallow and flat.

[grump]

Here is what I tried and it dosen't make sense to me. I have 1816'2 that I use with my Grizzly in 3 lengths. 28" , 28 3/16" , 28 3/8"
shot 2 fletched  and 2 unfletched of each with 75gr , 100gr , 125gr points.
The only ones that the fletched and unfletched grouped reasonably close was 28" with 75gr points. According to Stu's program that puts the dynamic spine of the arrow at 56.3 and the Montana needing an arrow with a dynamic spine of 41.2.
What am I doing wrong?

[Mike Mecredy]

It's not the shelf then, not as shallow cut as they are and shooting better with a stiffer arrow. Got me, makes no sence.

[grump]

Thanks guys. I don't know what I was doing the last time I tried to tune this Montana. I went over all your comments and suggestions and went to try to tune again. It ended up that with 28 1/4" 1816's with 3" fletching and 125gr points I get a very acceptable group. The fistmele was a bit over 8.5" so I brought it down to 7.5(much smoother)had to adjust the nock as well.
I'm quite happy with the results. Thanks for all your help and patience with me.

[nineworlds9]

oh yeah 8.5 was def too much, 7.5 waay better glad to hear its working

[Looper]

I'd think you'd need around a 30# spined cedar and a 125grain point, if you go with a 28" arrow.  If you want to go with a shorter arrow, go up a step in point weight for every inch shorter. So for a 27" arrow, use a 145gr point. For a 26", go with a 160gr point. Alternately, you can drop a spine group for each inch shorter, but I think you might have a hard time finding shafts under 30# in spine.

For the 1816s, you'll probably be close with 145 grain points at 28.25". Again, if you want to go shorter, go up a step for each inch you shorten.

If you want to try carbons, a good place to start would be the Gold Tip 1535s. Get a selection of points all the way up to 250 grains. Of course, you'll need to go through the tuning process, but I'm betting you'll need a lot of weight up front, 200-250grs.

[ron w]

Originally posted by mcgroundstalker:
A quick fix would be more point weight up front... Try your 50-55 POC with maybe a 200gr. tip.      

That's what I'm thinking also!